Tomato rootstock variety &#39;rts-123&#39;

ABSTRACT

Tomato rootstock variety designated ‘RTS-123’ is disclosed. The invention relates to the seeds of tomato rootstock ‘RTS-123’, to the plants of tomato rootstock ‘RTS-123’, and to methods for producing plants, and to methods for producing other tomato rootstock lines, cultivars, or hybrids derived from the tomato rootstock ‘RTS-123’.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.62/088,407, filed Dec. 5, 2014, which is hereby incorporated byreference in its entirety.

FIELD

This invention relates to the field of plant breeding. In particular,this invention relates to new and distinctive tomato, Solanumlycopersicon, rootstock variety designated ‘RTS-123’.

BACKGROUND

Cultivated and commercial forms of tomato generally belong to a speciesmost frequently referred to as Lycopersicon esculentum Miller (alsoknown as Solanum lycopersicum) that is grown for its fruit and which iswidely used as a fresh market or processed product. As a crop, tomato isgrown commercially wherever environmental conditions permit theproduction of an economically viable yield. The size of tomato fruitsmay range from small to large and there are cherry, plum, pear,standard, and beefsteak types. Tomatoes may be grouped by the amount oftime it takes for the plants to mature fruit for harvest; in general thecultivars are considered to be early, midseason or late-maturing.Tomatoes can also be grouped by the plant's growth habit, which can bedeterminate or indeterminate. Determinate plants tend to grow theirfoliage first, then set flowers that mature into fruit if pollination issuccessful. All of the fruit tend to ripen on a plant at about the sametime. Indeterminate tomatoes start out by growing some foliage, thencontinue to produce foliage and flowers throughout the growing season.These plants will tend to have tomato fruit in different stages ofmaturity at any given time. More recent developments in tomato breedinghave led to a wider array of fruit color. In addition to the standardred ripe color, tomatoes can be creamy white, lime green, pink, yellow,golden, or orange.

The first largest processing market and second largest fresh market fortomatoes in the United States is in California, where processingtomatoes are harvested by machine. The majority of fresh market tomatoesare harvested by hand at vine ripe and mature green stages of ripeness.Fresh market tomatoes are available in the United States year round.Process tomato season in California is from late June to October.Process tomatoes are used in many forms, as canned tomatoes, tomatojuice, tomato sauce, puree, paste and catsup. Of the 500,000 acres oftomatoes that are grown annually in the US, approximately 40% are grownfor fresh market consumption, while the remaining are grown forprocessing.

Lycopersicon is a relatively small genus within the extremely large anddiverse family Solanaceae, which is considered to consist of around 90genera including pepper, tobacco, and eggplant. The genus Lycopersiconhas been divided into two subgenera, the esculentum complex whichcontains those species that can easily be crossed with the commercialtomato and the peruvianum complex which contains those species which arecrossed with considerable difficulty (Stevens, M., and Rick, C. M. 1986.Genetics and Breeding. In: The Tomato Crop. A scientific basis forimprovement, pp. 35-109. Atherton, J., Rudich, G. (eds.). Chapman andHall, New York). Due to its value as a crop, L. esculentum Miller hasbecome widely disseminated all over the world. Even if the preciseorigin of the cultivated tomato is still somewhat unclear, it seems tocome from the Americas, being native to Ecuador, Peru and the GalapagosIslands and initially cultivated by Aztecs and Incas as early as 700 AD.Mexico appears to have been the site of domestication and the source ofthe earliest introduction. It is thought that the cherry tomato, L.esculentum var. cerasiforme, is the direct ancestor of modern cultivatedforms.

Tomato grafting has been utilized in Asia and Europe for greenhouse andhigh tunnel production and is gaining popularity in the United States.One advantage of grafting is that rootstocks may be used that provide orincrease resistance against, for example, fungal and viral diseases. Inaddition to providing or increasing resistance against such diseases,the use of grafting may also increase tolerance against differentabiotic stresses, such as drought tolerance, salinity tolerance,flooding/water tolerance and heat and cold temperature tolerance. Thereare several methods for grafting tomatoes. The most common graftingmethods include tongue approach/approach graft, holeinsertion/terminal/top insertion graft, one cotyledon/slant/splice/tubegraft, and cleft/side insertion graft.

Tomato is a simple diploid species with twelve pairs of differentiatedchromosomes. The cultivated tomato is self-fertile and almostexclusively self-pollinating. The tomato flowers are hermaphrodites.Commercial cultivars were initially open-pollinated, but most have nowbeen replaced by better yielding hybrids. Due to its wide disseminationand high value, tomato has been intensively bred.

It is becoming more and more challenging for farmers globally to satisfythe increasing worldwide demand for food. Progressively adverseenvironmental conditions steadily decrease available arable land.Furthermore, a growing global population presents serious challenges tothe agricultural industry. Thus, there is a need to overcome the currentconstraints (e.g., land, water, etc.) and reduce the risks of climatevolatility. Improving crop production is essential to the future ofsustainable agriculture.

Current agricultural systems use traditional breeding methods ortransgenic technologies to develop improved plant varieties. Presentlylacking is a breeding method which places emphasis on the plant organ(the root) responsible for supplying vital nutrients to the plant, thusdirectly impacting the plant's ultimate performance, yield, and itsability to tolerate abiotic stress.

Tomato is an important and valuable vegetable crop. Thus, there is acontinued need for new tomato varieties. In particular, there is a needfor an improved non-GMO tomato rootstock variety that is stable, highyielding, and agronomically sound. A rootstock variety that is tolerantto abiotic stress conditions (for example, cold, heat, salinity and/ordrought) and can overcome sub-optimal growing conditions that limit cropyield, for example for growing processing tomatoes, is also needed.

SUMMARY

In order to meet this need, the present invention provides improvedtomato rootstock variety designated ‘RTS-123’. This tomato rootstockvariety is graft compatible with tomato scion cultivars and othervegetable crop scions including pepper, eggplant and potato, and conferresistance and/or tolerance to cold stress and increased yield ongrafted plants. The rootstock variety disclosed herein is unique in thatit is useful for grafting greenhouse tomatoes and processing tomatoes.For greenhouse tomatoes a ton/dunam increase of up to 20% has beenobtained. For processing tomatoes a ton/acre yield increase of up to100% has been obtained.

The tomato rootstock variety designated ‘RTS-123’ may be grafted with ascion utilizing any suitable grafting methodology known in the art.Examples of suitable grafting methodologies include, without limitation,cleft grafting, approach grafting, micrografting, tube grafting, sideinsertion grafting, and top insertion grafting. Cleft grafting involvescutting a V-shape into the rootstock and inserting a complementingwedge-shaped scion. The graft may be then held with a small clip untilhealing occurs. Approach grafting, also known as tongue approachgrafting (TAG), involves notching opposing sides of the stems of therootstock and scion, and then using a clip to hold the stems togetherwhile they fuse. Once the graft has healed, the scion of the desiredrootstock plant may be removed above the graft site, and the unusedrootstock from scion plant may be detached from the scion below thegraft site. Micrografting, also known as splice grafting, is a techniquethat has been recently integrated into micropropagation production forhybrid tomato. Micrografting involves utilizing micropropagated scionshoots that may be grafted onto approximately three week-old rootstockseedlings. In some embodiments, micrografting is utilized for commercialscale tomato grafting. Tube grafting involves severing the scion androotstock as seedlings and attaching the severed rootstock seedling tothe severed scion seedling with a small, silicone tube with or without aclip. Tube grafting can be highly effective, as it may be carried outwhen plants are very small, thereby eliminating the need for largehealing chambers while increasing the output. Although less frequentlyused on a commercial scale, side insertion grafting and top insertiongrafting are also contemplated herein.

In one embodiment, the present invention is directed to seed of a tomatorootstock designated as ‘RTS-123’ having ATCC Accession Number X1. Inone embodiment, the present invention is directed to a tomato plant andparts isolated therefrom produced by growing ‘RTS-123’ tomato rootstockseed. In another embodiment, the present invention is directed to atomato plant and parts isolated therefrom, or a transgenic tomato plantand parts isolated therefrom, having all the physiological andmorphological characteristics of a tomato plant produced by growing‘RTS-123’ tomato rootstock seed having ATCC Accession Number X1. Instill another embodiment, the present invention is directed to an F₁hybrid tomato seed, plants grown from the seed, and rootstocks, leaves,ovules, pollen, fruit, cotyledons, embryos, meristems, anthers, roots,root tips, pistils, flowers, stems, calli, stalks, hypocotyla, andpericarps isolated therefrom having tomato rootstock variety ‘RTS-123’as a parent, wherein ‘RTS-123’ is grown from ‘RTS-123’ tomato rootstockseed having ATCC Accession Number X1. In some embodiments, the F₁ hybridis a transgenic plant. In another embodiment, the present invention isdirected to a tomato plant and parts isolated therefrom having all thephysiological and morphological characteristics of a tomato plantproduced by growing ‘RTS-123’ tomato rootstock seed having ATCCAccession Number X1. In some embodiments, the tomato plant is atransgenic plant. In still another embodiment, the present invention isdirected to an F₁ hybrid tomato seed, plants grown from the seed, androotstocks, leaves, ovules, pollen, fruit, cotyledons, embryos,meristems, anthers, roots, root tips, pistils, flowers, stems, calli,stalks, hypocotyla, and pericarps isolated therefrom having ‘RTS-123’ asa parent, wherein ‘RTS-123’ is grown from ‘RTS-123’ tomato rootstockseed having ATCC Accession Number X1. In some embodiments, the plantgrown from the F₁ hybrid seed is a transgenic plant.

Tomato plant parts include rootstocks, leaves, ovules, pollen, fruit,cotyledons, embryos, meristems, anthers, roots, root tips, pistils,flowers, stems, calli, stalks, hypocotyla, pericarps, and the like. Inanother embodiment, the present invention is further directed to tomatofruit, rootstocks, stems, leaves, parts of leaves, roots, root tips,pollen, ovules, and flowers isolated from plants of tomato rootstock‘RTS-123’ In another embodiment, the present invention is furtherdirected to rootstocks derived from ‘RTS-123’ tomato plants. In anotherembodiment, the present invention is further directed to tissue cultureor cells derived from plants of tomato rootstock ‘RTS-123’.

In yet another embodiment, the present invention is further directed toa method of selecting tomato plants by a) growing ‘RTS-123’ tomatorootstock plants wherein the ‘RTS-123’ plants are grown from tomato seedhaving ATCC Accession Number X1; and b) selecting a plant from step a).In another embodiment, the present invention is further directed totomato plants, plant parts and seeds produced by the tomato plants,where the tomato plants are isolated by the selection method of theinvention. In another embodiment, the present invention is furtherdirected to a method of breeding tomato plants by crossing a tomatoplant with a plant grown from ‘RTS-123’ tomato rootstock seed havingATCC Accession Number X1. In some embodiments, at least one of theplants of the crossing is a transgenic plant. In still anotherembodiment, the present invention is further directed to tomato plants,tomato parts from the tomato plants, and seeds produced therefrom wherethe tomato plant is isolated by the breeding method of the invention.

In yet another embodiment, provided herein is a tomato plant comprisinga rootstock and a scion engrafted onto the rootstock, wherein saidrootstock is from tomato rootstock variety designated ‘RTS-123’. In yetanother embodiment, provided herein is a method of producing a tomatoplant comprising a) providing a ‘RTS-123’ rootstock; and b) graftingonto the ‘RTS-123’ rootstock a scion, thereby generating a tomato plant.In preferred embodiments, the scion is a heterologous Solanumlycopersicon scion for growing greenhouse or open field, fresh market orprocessing tomatoes.

BRIEF DESCRIPTION OF THE DRAWINGS

The patent or application file contains at least one drawing executed incolor. Copies of this patent or patent application publication withcolor drawings will be provided by the office upon request and paymentof the necessary fee.

FIG. 1 illustrates a 68 day old plant from the tomato rootstock variety‘RTS-123’. In the photograph, each square on the sheet is 10 cm².

FIG. 2A and FIG. 2B illustrate leaves from the tomato rootstock variety‘RTS-123’. FIG. 2A shows the abaxial view of the leaves. FIG. 2B showsthe adaxial view of the leaves. In the photographs, each square on thesheet is 1 cm².

FIG. 3 illustrates inflorescence from the tomato rootstock variety‘RTS-123’. In the photograph, each square on the sheet is 1 cm².

FIG. 4 illustrates a flower from the tomato rootstock variety ‘RTS-123’.In the photograph, each square on the sheet is 1 cm².

FIG. 5 illustrates fruit from the tomato rootstock variety ‘RTS-123’. Inthe photograph, each square on the sheet is 1 cm².

FIGS. 6A and 6B depict a representative photograph of a field showingthe difference in growth between grafted tomato plants of tomatorootstock variety ‘RTS-123’ (FIG. 6A) and cultivated tomato plants (FIG.6B). The white dotted line represents a demarcation between the graftedand cultivated plants. All plants were planted in parallel in a field inCalifornia.

DETAILED DESCRIPTION Definitions

In the description and tables that follow, a number of terms are used.In order to provide a clear and consistent understanding of thespecification and claims, the following definitions are provided.

Allele: The allele is any of one or more alternative form of a gene, allof which alleles relates to one trait or characteristic. In a diploidcell or organism, the two alleles of a given gene occupy correspondingloci on a pair of homologous chromosomes.

Attachment point: The point on the tomato fruit where the fruit isconnected to the tomato plant.

Backcrossing: Backcrossing is a process in which a breeder repeatedlycrosses hybrid progeny back to one of the parents, for example, a firstgeneration hybrid F₁ with one of the parental genotypes of the F₁hybrid.

BRIX: Means a percentage by weight of the fruit of sugar in solutionmeasured using a refractometer, wherein the fruit is cut in half and thejuice within the fruit is squeezed onto a lens. The juice on the lens isthen measured by the refractometer.

Determinate tomato: A variety that comes to fruit all at once, thenstops bearing. Determinate varieties are best suited for commercialgrowing since they can be harvested all at once.

Essentially all the physiological and morphological characteristics: Aplant having essentially all the physiological and morphologicalcharacteristics of another plant means a plant having the physiologicaland morphological characteristics, except for the characteristicsderived from the converted gene, of the other plant.

Flesh color: The color of the tomato flesh that can range fromorange-red to dark red when at ripe stage (harvest maturity).

Fruit: A ripened ovary, together with any other structures that ripenwith the ovary and form a unit.

Grafting: Grafting refers to attaching tissue from one plant to anotherplant so that the vascular tissues of the two tissues join together.

pH: The pH is a measure of, e.g., fruit acidity. A pH under 4.35 isdesirable to prevent bacterial spoilage of finished products. pH risesas fruit matures.

Plant part: A plant part means any part of a plant including, forexample, a cell, protoplast, embryo, pollen, ovule, flower, leaf, stem,cotyledon, hypocotyl, meristematic cell, root, root tip, pistil, anther,shoot tip, shoot, fruit and petiole.

Predicted paste bostwick: The predicted paste bostwick is the flowdistance of tomato paste diluted to 12 degrees brix and heated prior toevaluation. Dilution to 12 degrees brix for bostwick measurement is astandard method used by industry to evaluate product consistency. Thelower the number, the thicker the product and therefore more desirablein consistency oriented products such as catsup. The following formulais usually used to evaluate the predicted paste bostwick: Predictedpaste bostwick=−11.53+(1.64*juice brix)+(0.5*juice bostwick).

Regeneration: Regeneration refers to the development of a plant fromtissue culture.

Relative maturity: Relative maturity is an indication of time until atomato genotype is ready for harvest. A genotype is ready for harvestwhen 90% or more of the tomatoes are ripe.

Rootstock: A root and its associated growth buds, used as a stock inplant propagation. As disclosed herein, such roots may be selected froma plant, for example for the resistance of its roots to diseases orstress (e.g., heat, cold, salinity etc.).

Scion: A part of a plant that is attached to a rootstock. A scion plantmay be selected for its stems, leaves, flowers, or fruits. A selectedscion may be used with the disclosed variety for greenhouse or openfield, fresh market or processing tomatoes.

Semi-erect habit: A semi-erect plant has a combination of lateral andupright branching and has an intermediate-type habit between a prostateplant habit, having laterally growing branching with fruits most of thetime on the ground and an erect plant habit has branching going straightup with fruit being off the ground.

Single gene converted: Single gene converted or conversion plant refersto plants which are developed by a plant breeding technique calledbackcrossing wherein essentially all of the desired morphological andphysiological characteristics of an inbred are recovered in addition tothe single gene transferred into the inbred via the backcrossingtechnique or via genetic engineering.

Soluble Solids: Soluble solids refer to the percent of solid materialfound in the fruit tissue, the vast majority of which is sugars. Solublesolids are directly related to finished processed product yield ofpastes and sauces. Soluble solids are estimated with a refractometer,and measured as degrees brix.

Quantitative Trait Loci (QTL): Quantitative trait loci refer to geneticloci that control to some degree numerically representable traits thatare usually continuously distributed.

Uniform ripening: Refers to a tomato that ripens uniformly, i.e., onethat has no green discoloration on the shoulders. The uniform ripeningis controlled by a single recessive gene.

Vegetative propagation: Means taking part of a plant and allowing thatplant part to form roots where plant part is defined as leaf, pollen,embryo, cotyledon, hypocotyl, meristematic cell, root, root tip, pistil,anther, flower, shoot tip, shoot, stem, fruit and petiole.

Viscosity: The viscosity or consistency of tomato products is affectedby the degree of concentration of the tomato, the amount of and extentof degradation of pectin, the size, shape and quality of the pulp, andprobably to a lesser extent, by the proteins, sugars and other solubleconstituents. The viscosity is measured in Bostwick centimeters by usinginstruments such as a Bostwick Consistometer.

Overview of Tomato Rootstock Variety ‘RTS-123’

Described herein is a new and distinct tomato rootstock variety named‘RTS-123’, which has superior characteristics. In one embodiment, tomatoplants of tomato rootstock variety ‘RTS-123’ exhibit tolerance and/orresistance to cold stress (e.g., exhibits continuous development inchilling temperatures and/or frost), confers tolerance and/or resistanceto cold stress to grafted plants, and confers increased scion yieldswhen grafted.

The tomato rootstock variety ‘RTS-123’ is uniform and stable withincommercially acceptable limits. As is true with other tomato varieties,a small percentage of variants can occur within commercially acceptablelimits for almost any characteristic during the course of repeatedmultiplication. However no variants were observed during the two yearsin which the variety was observed to be uniform and stable.

Characterization of Tomato Rootstock Variety ‘RTS-123’ Seedling

Anthocyanin in hypocotyl of 2-15 cm seedling: PresentHabit of 3-4 week old seedling: Compact

Mature Plant

FIG. 1 is a photograph of a representative plant of tomato rootstockvariety ‘RTS-123’.Average height (in cm): 200 cm

Growth: Indeterminate Form: Normal

Size of canopy (compared to others of similar type): Large

Habit: Semi-erect Stem

Average length (in cm): 200 cm

Branching: Spares

Branching at cotyledonary or first leafy node: AbsentNumber of nodes between first inflorescence: 10Number of nodes between early (1st-2nd, 2nd-3rd) inflorescences: 3Number of nodes between later developing inflorescences: 3Pubescence on younger stems: Moderately hairyLeaf (mature leaf beneath the 3rd inflorescence)FIGS. 2A and 2B are representative photographs showing abaxial andadaxial views, respectively, of leaves of tomato rootstock variety‘RTS-123’.

Type: Tomato

Morphology of mature leaf: BipinnateAverage length and width (in cm): Length: 20 cm; Width: 30 cmMargins of major leaflets: Shallowly toothed or scallopedMarginal rolling or wiltiness: AbsentOnset of leaflet rolling: Late seasonSurface of major leaflets: Rugose (bumpy or veiny)

Pubescence: Hirsute

Leaf attitude: HorizontalInflorescence (make observations on 3rd inflorescence)FIG. 3 is a photograph showing characteristic inflorescence of the plantof tomato rootstock variety ‘RTS-123’.Type: Compound (much branched)Average number of flowers in inflorescence: 25Leafy or “running” inflorescences: Occasional

Flower

FIG. 4 is a photograph showing a characteristic flower of the plant oftomato rootstock variety ‘RTS-123’.Calyx: Normal, lobes awl-shapedCalyx-lobes: Approx. equalling corollaCorolla color: YellowStyle pubescence: Absent

Anthers: Open

Fasciation (1st flower of 2nd or 3rd inflorescence): OccasionallypresentFruit (3rd fruit of 2nd or 3rd cluster)FIG. 5 is a photograph showing characteristic fruit of tomato rootstockvariety ‘RTS-123’.Typical fruit shape: RoundShape of transverse section: RoundShape of stem end: NormalShape of blossom end: RoundShape of pistil scar: RoundAbscission layer: Present (pedicellate)Point of detachment of fruit at harvest: At pedicel jointAverage length (in mm) of dedicel (from joint to calyx attachment): 5 mmAverage length (in mm) of mature fruit (stem axis): 12 mmAverage diameter (in mm) of fruit at widest point: 30 mmAverage weight (in g) of mature fruit: 15 gNumber of locules: TwoFruit surface: SmoothFruit base color (mature-green stage): Light green (e.g., ‘Lanai’, ‘VF145-F5’)Fruit pattern (mature-green stage): Moderately conspicuous radialstripes on sides of fruitFruit color, full-ripe: GreenishFlesh color full-ripe: GreenFlesh color: UniformLocular gel color of table-ripe fruit: Green

Ripening: Uniform

Stem scar size: Small (e.g., ‘Roma’)Core: Coreless (absent or smaller than 6×6 mm)Epidermis color: Colorless

Epidermis: Normal

Epidermis texture: ToughThickness of the pericarp: Slightly fleshy

Phenology

Fruiting season: Long (e.g., ‘Marglobe’)Relative maturity in areas tested: Variable

Adaptation Culture: Greenhouse

Principle use(s): RootstockMachine harvest: AdaptedRegions to which adaptation has been demonstrated: California:Sacramento and Upper San Joaquin Valley; California: Southern SanJoaquin Valley, and deserts.

FIGS. 6A and 6B depict a representative photograph of a field of graftedplants of tomato rootstock variety ‘RTS-123’ (FIG. 6A) and cultivatedtomato plants (FIG. 6B). All plants were planted in parallel in a fieldin California in which the well unexpectedly dried out in mid-season.The plants are shown at the end of July. The cultivated plants shown inFIG. 6B remain stunted and partially desiccated, while the graftedplants of tomato rootstock variety designated ‘RTS-123’ are large andgreen (FIG. 6A).

Tables 1A and 1B provide a comparison in yields (T/A refers to ton/acre)ungrafted control tomato plants and the grafted plants of tomatorootstock variety designated ‘RTS-123’ grown in California in ninedifferent fields. A total of 1,876,000 of grafted plants of tomatorootstock variety designated ‘RTS-123’ and 474,000 ungrafted controlplants were planted in nine fields in Northern California. The term Δ %refers to the difference in yield between the grafted and ungraftedplants.

TABLE 1A LA 7 West LA 7 East LB LF LC Yield Yield Yield Yield YieldRootstock (T/A) Δ % (T/A) Δ % (T/A) Δ % (T/A) Δ % (T/A) Δ % Ungrafted 3056 36 40 89 control RTS-123 57.1 90.5 54.6 −2.8 45.7 27.6 44.0 9.5 83.6−5.6

TABLE 1B Field LM LS LAm 5608 LAm 6404 Yield Yield Yield Yield Rootstock(T/A) Δ % (T/A) Δ % (T/A) Δ % (T/A) Δ % Ungrafted 43 80 49 50 controlRTS-123 52.6 21.4 80.1 −0.4 58.1 19.8 52.9 6.4

Comparison to Most Similar Variety

Table 2 below compares some of the characteristics of tomato rootstockvariety ‘RTS-123’ with similar variety, ‘Maxifort’. Column 1 lists thecharacteristics, column 2 shows the characteristics for tomato rootstockvariety ‘RTS-123’, and column 3 shows the characteristics for mostsimilar tomato variety ‘Maxifort’.

TABLE 2 Characteristic ‘RTS-123’ ‘Maxifort’ Leaf width Narrow Broad Leafhirsuteness High Low Leaf coverage Low Medium-high

Further Embodiments

This present disclosure is also directed to methods for producing atomato plant by crossing a first parent tomato plant with a secondparent tomato plant where either the first or second parent tomato plantis a tomato plant of tomato rootstock variety ‘RTS-123’. Further, bothfirst and second parent tomato plants can come from a tomato plant oftomato rootstock variety ‘RTS-123’. All plants produced using a tomatoplant of tomato rootstock variety ‘RTS-123’ as a parent are within thescope of the disclosure, including plants derived from a tomato plant oftomato rootstock variety ‘RTS-123’ (‘RTS-123’-derived plant). Further,the disclosure is directed to methods for producing a tomato plantderived from a tomato plant of tomato rootstock variety ‘RTS-123’ bycrossing a tomato plant of tomato rootstock variety ‘RTS-123’ with asecond tomato plant and growing the progeny seed, and repeating thecrossing and growing steps with the ‘RTS-123’-derived plant from 0 to 7times. Thus, any such methods using a tomato plant of tomato rootstockvariety ‘RTS-123’ are included in this disclosure: selfing, backcrosses,hybrid production, crosses to populations, and the like. Plants producedusing a tomato plant of tomato rootstock variety ‘RTS-123’ as a parentare presented herein, including plants derived from a tomato plant oftomato rootstock variety ‘RTS-123’. Advantageously, a tomato plant oftomato rootstock variety ‘RTS-123’ may be used in crosses with othertomato plants including, for example, other tomato hybrids, to producefirst generation (F₁) tomato hybrid seeds and plants with superiorcharacteristics.

As used herein, the term plant includes plant cells, plant protoplasts,plant cell tissue cultures from which tomato plants can be regenerated,plant calli, plant clumps and plant cells that are intact in plants orparts of plants, such as embryos, pollen, ovules, flowers, leaves,stems, and the like.

With the advent of molecular biological techniques that have allowed theisolation and characterization of genes that encode specific proteinproducts, scientists in the field of plant biology developed a stronginterest in engineering plant genomes to contain and express foreigngenes, or additional, or modified versions of native, or endogenous,genes (perhaps driven by different promoters) in order to alter thetraits of a plant in a specific manner. Such foreign additional and/ormodified genes are referred to herein collectively as “transgenes.”Several methods for producing transgenic plants have been developed, andthe present disclosure, in particular embodiments, also relates totransformed versions of plants. In particular, the present disclosurerelates to transformed versions of tomato rootstock variety ‘RTS-123’.

Plant transformation involves the construction of an expression vectorthat will function in plant cells. Such a vector contains DNA includinga gene under control of or operatively linked to a regulatory element(for example, a promoter). The expression vector may contain one or moresuch operably linked gene/regulatory element combinations. The vector(s)may be in the form of a plasmid, and can be used alone or in combinationwith other plasmids, to provide transformed tomato plants usingtransformation methods as described herein to incorporate transgenesinto the genetic material of the tomato plant(s).

Expression Vectors for Transformation of Tomato Rootstock Variety‘RTS-123’

Marker Genes

Expression vectors include at least one genetic marker operably linkedto a regulatory element (a promoter, for example) that allowstransformed cells containing the marker to be either recovered bynegative selection, i.e., inhibiting growth of cells that do not containthe selectable marker gene, or by positive selection, i.e., screeningfor the product encoded by the genetic marker. Many commonly usedselectable marker genes for plant transformation are well known in thetransformation arts, and include, for example, genes that code forenzymes that metabolically detoxify a selective chemical agent which maybe an antibiotic or an herbicide, or genes that encode an altered targetwhich is insensitive to the inhibitor. Positive selection methods arealso known in the art.

One commonly used selectable marker gene for plant transformation is theneomycin phosphotransferase II (nptII) gene, isolated from transposonTn5, which when placed under the control of plant regulatory signalswhich confers resistance to kanamycin (Fraley et al., Proc. Natl. Acad.Sci. U.S.A., 80:4803 (1983)). Another commonly used selectable markergene is the hygromycin phosphotransferase gene which confers resistanceto the antibiotic hygromycin (Vanden Elzen et al., Plant Mol. Biol.,5:299 (1985)).

Additional selectable marker genes of bacterial origin that conferresistance to antibiotics include gentamycin acetyl transferase,streptomycin phosphotransferase, aminoglycoside-3′-adenyl transferase,the bleomycin resistance determinant (Hayford et al., Plant Physiol.86:1216 (1988), Jones et al., Mol. Gen. Genet., 210:86 (1987), Svab etal., Plant Mol. Biol. 14:197 (1990), Hille et al., Plant Mol. Biol.7:171 (1986)). Other selectable marker genes confer resistance toherbicides such as glyphosate, glufosinate or bromoxynil (Comai et al.,Nature 317:741-744 (1985), Gordon-Kamm et al., Plant Cell 2:603-618(1990) and Stalker et al., Science 242:419-423 (1988)).

Selectable marker genes for plant transformation that are not ofbacterial origin include, for example, mouse dihydrofolate reductase,plant 5-enolpyruvylshikimate-3-phosphate synthase and plant acetolactatesynthase (Eichholtz et al., Somatic Cell Mol. Genet. 13:67 (1987), Shahet al., Science 233:478 (1986), Charest et al., Plant Cell Rep. 8:643(1990)).

Another class of marker genes for plant transformation requiresscreening of presumptively transformed plant cells rather than directgenetic selection of transformed cells for resistance to a toxicsubstance such as an antibiotic. These genes are particularly useful toquantify or visualize the spatial pattern of expression of a gene inspecific tissues and are frequently referred to as reporter genesbecause they can be fused to a gene or gene regulatory sequence for theinvestigation of gene expression. Commonly used genes for screeningpresumptively transformed cells include alpha-glucuronidase (GUS),alpha-galactosidase, luciferase and chloramphenicol, acetyltransferase(Jefferson, R. A., Plant Mol. Biol. Rep. 5:387 (1987), Teeri et al.,EMBO J. 8:343 (1989), Koncz et al., Proc. Natl. Acad. Sci U.S.A. 84:131(1987), DeBlock et al., EMBO J. 3:1681 (1984)).

In vivo methods for visualizing GUS activity that do not requiredestruction of plant tissues are available (Molecular Probes publication2908, IMAGENE GREEN, p. 1-4 (1993) and Naleway et al., J. Cell Biol.115:151 a (1991)). More recently, a gene encoding Green FluorescentProtein (GFP) has been utilized as a marker for gene expression inprokaryotic and eukaryotic cells (Chalfie et al., Science 263:802(1994)). GFP and mutants of GFP may be used as screenable markers.

Promoters

Genes included in expression vectors may be driven by a nucleotidesequence containing a regulatory element, for example, a promoter.Several types of promoters are well known in the transformation arts asare other regulatory elements that can be used alone or in combinationwith promoters.

As used herein, “promoter” includes reference to a region of DNAupstream from the start of transcription and involved in recognition andbinding of RNA polymerase and other proteins to initiate transcription.A “plant promoter” is a promoter capable of initiating transcription inplant cells. Examples of promoters under developmental control include,for example, promoters that preferentially initiate transcription incertain tissues such as leaves, roots, seeds, fibers, xylem vessels,tracheids, or sclerenchyma. Such promoters are referred to as“tissue-preferred.” Promoters that initiate transcription only in acertain tissue are referred to as “tissue-specific.” A “cell-type”specific promoter primarily drives expression in certain cell types inone or more organs, for example, vascular cells in roots or leaves. An“inducible” promoter is a promoter which is under environmental control.Examples of environmental conditions that may affect transcription byinducible promoters include, for example, anaerobic conditions or thepresence of light. Tissue-specific, tissue-preferred, cell typespecific, and inducible promoters constitute the class of“non-constitutive” promoters. A “constitutive” promoter is a promoterthat is active under most environmental conditions.

Inducible Promoters: An inducible promoter is operably linked to a genefor expression in tomato. Optionally, the inducible promoter is operablylinked to a nucleotide sequence encoding a signal sequence which isoperably linked to a gene for expression in tomato. Inducible promotersmay regulate transcription in response to an inducing agent.

Any inducible promoter can be used herein. See Ward et al., Plant Mol.Biol. 22:361-366 (1993). Exemplary inducible promoters may include, forexample, that from the ACEI system which responds to copper (Meft etal., Proc. Natl. Acad. Sci. U.S.A. 90:4567-4571 (1993)); In2 gene frommaize which responds to benzenesulfonamide herbicide safeners (Hersheyet al., Mol. Gen Genetics 227:229-237 (1991) and Gatz et al., Mol. Gen.Genetics 243:32-38 (1994)) or Tet repressor from Tn10 (Gatz et al., Mol.Gen. Genetics 227:229-237 (1991). A particularly preferred induciblepromoter is a promoter that responds to an inducing agent to whichplants do not normally respond. An exemplary inducible promoter is theinducible promoter from a steroid hormone gene, the transcriptionalactivity of which is induced by a glucocorticosteroid hormone. Schena etal., Proc. Natl. Acad. Sci. U.S.A. 88:0421 (1991).

Constitutive Promoters: A constitutive promoter is operably linked to agene for expression in tomato or the constitutive promoter is operablylinked to a nucleotide sequence encoding a signal sequence which isoperably linked to a gene for expression in tomato.

Many different constitutive promoters can be utilized herein. Exemplaryconstitutive promoters may include, for example, the promoters fromplant viruses such as the 35S promoter from CaMV (Odell et al., Nature313:810-812 (1985) and the promoters from such genes as rice actin(McElroy et al., Plant Cell 2:163-171 (1990)); ubiquitin (Christensen etal., Plant Mol. Biol. 12:619-632 (1989) and Christensen et al., PlantMol. Biol. 18:675-689 (1992)); pEMU (Last et al., Theor. Appl. Genet.81:581-588 (1991)); MAS (Velten et al., EMBO J. 3:2723-2730 (1984)) andmaize H3 histone (Lepetit et al., Mol. Gen. Genetics 231:276-285 (1992)and Atanassova et al., Plant Journal 2 (3): 291-300 (1992)). The ALSpromoter, Xba1/Nco1 fragment 5′ to the Brassica napus ALS3 structuralgene (or a nucleotide sequence similarity to said Xba1/Nco1 fragment),represents a particularly useful constitutive promoter. See PCTapplication WO 96/30530.

Tissue-specific or Tissue-preferred Promoters: A tissue-specificpromoter is operably linked to a gene for expression in tomato.Optionally, the tissue-specific promoter is operably linked to anucleotide sequence encoding a signal sequence which is operably linkedto a gene for expression in tomato. Plants transformed with a transgeneoperably linked to a tissue-specific promoter produce the transgenicprotein product exclusively, or preferentially, in a specific tissue.

Any tissue-specific or tissue-preferred promoter can be utilized herein.Exemplary tissue-specific or tissue-preferred promoters may include, forexample, a root-preferred promoter, such as that from the phaseolin gene(Mural et al., Science 23:476-482 (1983) and Sengupta-Gopalan et al.,Proc. Natl. Acad. Sci. U.S.A. 82:3320-3324 (1985)); a leaf-specific andlight-induced promoter such as that from cab or rubisco (Simpson et al.,EMBO J. 4(11):2723-2729 (1985) and Timko et al., Nature 318:579-582(1985)); an anther-specific promoter such as that from LAT52 (Twell etal., Mol. Gen. Genetics 217:240-245 (1989)); a pollen-specific promotersuch as that from Zm13 (Guerrero et al., Mol. Gen. Genetics 244:161-168(1993)) or a microspore-preferred promoter such as that from apg (Twellet al., Sex. Plant Reprod. 6:217-224 (1993)).

Signal Sequences for Targeting Proteins to Subcellular Compartments

The present disclosure further relates to transformed versions of tomatorootstock variety ‘RTS-123’ comprising a vector useful for targetingproteins to subcellular compartments using tissue specific promotors.Transport of a protein produced by transgenes to a subcellularcompartment such as the chloroplast, vacuole, peroxisome, glyoxysome,cell wall or mitochondrion or for secretion into the apoplast, isaccomplished by means of operably linking the nucleotide sequenceencoding a signal sequence to the 5′ and/or 3′ region of a gene encodingthe protein of interest. Targeting sequences at the 5′ and/or 3′ end ofthe structural gene may determine during protein synthesis andprocessing where the encoded protein is ultimately compartmentalized.

The presence of a signal sequence directs a polypeptide to either anintracellular organelle or subcellular compartment or for secretion tothe apoplast. Many signal sequences are known in the art. See, forexample Becker et al., Plant Mol. Biol. 20:49 (1992), Close, P. S.,Master's Thesis, Iowa State University (1993), Knox, C., et al.,“Structure and Organization of Two Divergent Alpha-Amylase Genes fromBarley”, Plant Mol. Biol. 9:3-17 (1987), Lerner et al., Plant Physiol.91:124-129 (1989), Fontes et al., Plant Cell 3:483-496 (1991), Matsuokaet al., Proc. Natl. Acad. Sci. 88:834 (1991), Gould et al., J. Cell.Biol. 108:1657 (1989), Creissen et al., Plant J. 2:129 (1991), Kalderonet al., Cell 39:499-509 (1984), Steifel et al., Plant Cell 2:785-793(1990).

Foreign Protein Genes and Agronomic Genes

With transgenic plants of tomato rootstock variety ‘RTS-123’ accordingto the present disclosure, a foreign protein can be produced incommercial quantities. Thus, techniques for the selection andpropagation of transformed plants, which are well understood in the art,yield a plurality of transgenic plants which are harvested in aconventional manner, and a foreign protein can then be extracted from atissue of interest or from total biomass. Protein extraction from plantbiomass can be accomplished by known methods which are discussed, forexample, by Heney and Orr, Anal. Biochem. 114:92-6 (1981).

According to a preferred embodiment, the transgenic plant provided forcommercial production of foreign protein is a tomato plant. For therelatively small number of transgenic plants that show higher levels ofexpression, a genetic map can be generated, primarily via conventionalRFLP, PCR and SSR analysis, which identifies the approximate chromosomallocation of the integrated DNA molecule. For exemplary methodologies inthis regard, see Glick and Thompson, Methods in Plant Molecular Biologyand Biotechnology, CRC Press, Boca Raton 269:284 (1993). Map informationconcerning chromosomal location is useful, for example, in geneticcomparisons where the genetic maps of two plants are compared. Wang etal. discuss “Large Scale Identification, Mapping and Genotyping ofSingle-Nucleotide Polymorphisms in the Human Genome,” Science,280:1077-1082, 1998, and similar capabilities are becoming increasinglyavailable for the tomato genome. Map comparisons may involve, forexample, hybridizations, RFLP, PCR, SSR and sequencing, all of which areconventional techniques. SNPs may also be used alone or in combinationwith other techniques.

Likewise, by means of the present disclosure, plants can be geneticallyengineered to express various phenotypes of horticultural interest.Through the transformation of tomato the expression of genes can bealtered to enhance disease resistance, insect resistance, herbicideresistance, horticultural quality and other traits. Transformation canalso be used to insert DNA sequences which control or help controlmale-sterility. DNA sequences native to tomato as well as non-native DNAsequences can be transformed into tomato and used to alter levels ofnative or non-native proteins. Various promoters, targeting sequences,enhancing sequences, and other DNA sequences can be inserted into thegenome for the purpose of altering the expression of proteins. Reductionof the activity of specific genes (also known as gene silencing, or genesuppression) is desirable for several aspects of genetic engineering inplants.

Many techniques for gene silencing are well known to one of skill in theart, including, for example, knock-outs (such as by insertion of atransposable element such as mu (Vicki Chandler, The Maize Handbook ch.118 (Springer-Verlag 1994) or other genetic elements such as a FRT, Loxor other site specific integration site, antisense technology (see,e.g., Sheehy et al. (1988) PNAS USA 85:8805-8809; and U.S. Pat. Nos.5,107,065; 5,453,566; and 5,759,829); co-suppression (e.g., Taylor(1997) Plant Cell 9:1245; Jorgensen (1990) Trends Biotech.8(12):340-344; Flavell (1994) PNAS USA 91:3490-3496; Finnegan et al.(1994) Bio/Technology 12: 883-888; and Neuhuber et al. (1994) Mol. Gen.Genet. 244:230-241); RNA interference (Napoli et al. (1990) Plant Cell2:279-289; U.S. Pat. No. 5,034,323; Sharp (1999) Genes Dev. 13:139-141;Zamore et al. (2000) Cell 101:25-33; and Montgomery et al. (1998) PNASUSA 95:15502-15507), virus-induced gene silencing (Burton, et al. (2000)Plant Cell 12:691-705; and Baulcombe (1999) Curr. Op. Plant Bio.2:109-113); target-RNA-specific ribozymes (Haseloff et al. (1988) Nature334: 585-591); hairpin structures (Smith et al. (2000) Nature407:319-320; WO 99/53050; and WO 98/53083); MicroRNA (Aukerman & Sakai(2003) Plant Cell 15:2730-2741); ribozymes (Steinecke et al. (1992) EMBOJ. 11:1525; and Perriman et al. (1993) Antisense Res. Dev. 3:253);oligonucleotide mediated targeted modification (e.g., WO 03/076574 andWO 99/25853); Zn-finger targeted molecules (e.g., WO 01/52620; WO03/048345; and WO 00/42219); and other methods or combinations of theabove methods known to those of skill in the art.

Likewise, by means of the present disclosure, other genes can beexpressed in transformed plants, such as transformed versions of atomato plant of tomato rootstock variety ‘RTS-123’. More particularly,plants can be genetically engineered to express various phenotypes ofinterest. Exemplary genes implicated in this regard may include, forexample, those categorized below.

Genes that Confer Resistance to Pests or Disease

Plant disease resistance genes: Plant defenses are often activated byspecific interaction between the product of a disease resistance gene(R) in the plant and the product of a corresponding avirulence (Avr)gene in the pathogen. A plant variety, such as a tomato variety, can betransformed with one or more cloned resistance genes to engineer plantsthat are resistant to specific pathogen strains. See, for example, Joneset al., Science 266:789 (1994) (cloning of the tomato Cf-9 gene forresistance to Cladosporium flavum); Martin et al., Science 262:1432(1993) (tomato Pto gene for resistance to Pseudomonas syringae pv.tomato encodes a protein kinase); Mindrinos et al. Cell 78:1089 (1994)(Arabidopsis RSP2 gene for resistance to Pseudomonas syringae), McDowell& Woffenden, (2003) Trends Biotechnol. 21(4): 178-83 and Toyoda et al.,(2002) Transgenic Res. 11 (6):567-82.

A gene conferring resistance to a pest, such as a nematode: See, forexample, PCT Application WO 96/30517; PCT Application WO 93/19181.

A Bacillus thuringiensis protein, a derivative thereof or a syntheticpolypeptide modeled thereon: See, for example, Geiser et al., Gene48:109 (1986), who disclose the cloning and nucleotide sequence of a Btδ-endotoxin gene. Moreover, DNA molecules encoding δ-endotoxin genes canbe purchased from American Type Culture Collection, Manassas, Va., forexample, under ATCC Accession Nos. 40098, 67136, 31995 and 31998.

A lectin: See, for example, Van Damme et al., Plant Molec. Biol. 24:25(1994), who disclose the nucleotide sequences of several Clivia miniatamannose-binding lectin genes.

A vitamin-binding protein, such as avidin: See, for example, PCTapplication US 93/06487 which teaches the use of avidin and avidinhomologues as larvicides against insect pests.

An enzyme inhibitor, for example, a protease or proteinase inhibitor oran amylase inhibitor: See, for example, Abe et al., J. Biol. Chem.262:16793 (1987) (nucleotide sequence of rice cysteine proteinaseinhibitor), Huub et al., Plant Molec. Biol. 21:985 (1993) (nucleotidesequence of cDNA encoding tobacco proteinase inhibitor I), Sumitani etal., Biosci. Biotech. Biochem. 57:1243 (1993) (nucleotide sequence ofStreptomyces nitrosporeus α-amylase inhibitor) and U.S. Pat. No.5,494,813 (Hepher and Atkinson, issued Feb. 27, 1996).

An insect-specific hormone or pheromone such as an ecdysteroid orjuvenile hormone, a variant thereof, a mimetic based thereon, or anantagonist or agonist thereof: See, for example, the disclosure byHammock et al., Nature 344:458 (1990), of baculovirus expression ofcloned juvenile hormone esterase, an inactivator of juvenile hormone.

An insect-specific peptide or neuropeptide which, upon expression,disrupts the physiology of the affected pest: For example, see thedisclosures of Regan, J. Biol. Chem. 269:9 (1994) (expression cloningyields DNA coding for insect diuretic hormone receptor), and Pratt etal., Biochem. Biophys. Res. Comm. 163:1243 (1989) (an allostatin isidentified in Diploptera puntata); Chattopadhyay et al. (2004) CriticalReviews in Microbiology 30 (1): 33-54 2004; Zjawiony (2004) J Nat Prod67 (2): 300-310; Carlini & Grossi-de-Sa (2002) Toxicon, 40 (11):1515-1539; Ussuf et al. (2001) Curr Sci. 80 (7): 847-853; andVasconcelos & Oliveira (2004) Toxicon 44 (4): 385-403. See also U.S.Pat. No. 5,266,317 to Tomalski et al., which discloses genes encodinginsect-specific, paralytic neurotoxins.

An insect-specific venom produced in nature by a snake, a wasp, etc. Forexample, see Pang et al., Gene 116:165 (1992), for disclosure ofheterologous expression in plants of a gene coding for a scorpioninsectotoxic peptide.

An enzyme responsible for hyperaccumulation of a monoterpene, asesquiterpene, a steroid, hydroxamic acid, a phenylpropanoid derivativeor another non-protein molecule with insecticidal activity.

An enzyme involved in the modification, including the post-translationalmodification, of a biologically active molecule; for example, aglycolytic enzyme, a proteolytic enzyme, a lipolytic enzyme, a nuclease,a cyclase, a transaminase, an esterase, a hydrolase, a phosphatase, akinase, a phosphorylase, a polymerase, an elastase, a chitinase and aglucanase, whether natural or synthetic: See, for example, PCTapplication WO 93/02197 (Scott et al.), which discloses the nucleotidesequence of a callase gene. DNA molecules which containchitinase-encoding sequences can be obtained from the ATCC underAccession Nos. 39637 and 67152. See also Kramer et al., Insect Biochem.Molec. Biol. 23:691 (1993), who teach the nucleotide sequence of a cDNAencoding tobacco hornworm chitinase, and Kawalleck et al., Plant Molec.Biol. 21:673 (1993), who provide the nucleotide sequence of the parsleyubi4-2 polyubiquitin gene, U.S. Pat. Nos. 7,145,060, 7,087,810 and6,563,020.

A molecule that stimulates signal transduction. For example, see thedisclosure by Botella et al., Plant Molec. Biol. 24:757 (1994), ofnucleotide sequences for mung bean calmodulin cDNA clones, and Griess etal., Plant Physiol. 104:1467 (1994), who provide the nucleotide sequenceof a maize calmodulin cDNA clone.

A hydrophobic moment peptide: See, for example, PCT application WO95/16776 and U.S. Pat. No. 5,580,852, which disclose peptide derivativesof tachyplesin which inhibit fungal plant pathogens, and PCT applicationWO 95/18855 and U.S. Pat. No. 5,607,914 which teaches syntheticantimicrobial peptides that confer disease resistance.

A membrane permease, a channel former or a channel blocker. For example,see the disclosure of Jaynes et al., Plant Sci 89:43 (1993), ofheterologous expression of a cecropin-β lytic peptide analog to rendertransgenic tobacco plants resistant to Pseudomonas solanacearum.

A viral-invasive protein or a complex toxin derived therefrom. Forexample, the accumulation of viral coat proteins in transformed plantcells imparts resistance to viral infection and/or disease developmenteffected by the virus from which the coat protein gene is derived, aswell as by related viruses. See Beachy et al., Ann. Rev. Phytopathol.28:451 (1990). Coat protein-mediated resistance has been conferred upontransformed plants against alfalfa mosaic virus, cucumber mosaic virusand tobacco mosaic virus.

An insect-specific antibody or an immunotoxin derived therefrom. Thus,an antibody targeted to a critical metabolic function in the insect gutwould inactivate an affected enzyme, killing the insect. See, forexample, Taylor et al., Abstract #497, Seventh Int'l Symposium onMolecular Plant-Microbe Interactions (Edinburgh, Scotland) (1994)(enzymatic inactivation in transgenic tobacco via production ofsingle-chain antibody fragments).

A virus-specific antibody: See, for example, Tavladoraki et al., Nature366:469 (1993), who show that transgenic plants expressing recombinantantibody genes are protected from virus attack.

A developmental-arrestive protein produced in nature by a pathogen or aparasite. Thus, fungal endo-α-1,4-D-polygalacturonases facilitate fungalcolonization and plant nutrient release by solubilizing plant cell wallhomo-α-1,4-D-galacturonase. See, for example, Lamb et al.,Bio/Technology 10:1436 (1992). The cloning and characterization of agene which encodes a bean endopolygalacturonase-inhibiting protein isdescribed by Toubart et al., Plant J. 2:367 (1992).

A developmental-arrestive protein produced in nature by a plant. Forexample, Logemann et al., Bio/Technology 10:305 (1992), have shown thattransgenic plants expressing the barley ribosome-inactivating gene havean increased resistance to fungal disease.

Genes involved in the Systemic Acquired Resistance (SAR) Response and/orthe pathogenesis-related genes. For example, see Briggs, S., CurrentBiology, 5(2) (1995); Pieterse & Van Loon (2004) Curr. Opin. Plant Bio.7(4):456-64 and Somssich (2003) Cell 113(7):815-6.

Antifungal genes: See Cornelissen and Melchers, Plant Physiol.,101:709-712 (1993); Parijs et al., Planta 183:258-264 (1991) andBushnell et al., Can. J. of Plant Path. 20(2):137-149 (1998). Also seeU.S. Pat. No. 6,875,907.

Detoxification genes, such as for fumonisin, beauvericin, moniliforminand zearalenone and their structurally related derivatives. For example,see U.S. Pat. No. 5,792,931.

Cystatin and cysteine proteinase inhibitors: See, for example, U.S. Pat.No. 7,205,453.

Defensin genes: See, for example, WO 03/000863 and U.S. Pat. No.6,911,577.

Genes conferring resistance to nematodes: See, for example, PCTApplication WO 96/30517; PCT Application WO 93/19181, WO 03/033651 andUrwin et al., Planta 204:472-479 (1998), Williamson (1999) Curr OpinPlant Bio. 2(4):327-31.

Genes that confer resistance to Phytophthora root rot, such as the Rps1, Rps 1-a, Rps 1-b, Rps 1-c, Rps 1-d, Rps 1-e, Rps 1-k, Rps 2, Rps 3-a,Rps 3-b, Rps 3-c, Rps 4, Rps 5, Rps 6, Rps 7 and other Rps genes. See,for example, Shoemaker et al., Phytophthora Root Rot Resistance GeneMapping in Soybean, Plant Genome IV Conference, San Diego, Calif.(1995).

Genes that confer resistance to Brown Stem Rot: See, for example, thosedescribed in U.S. Pat. No. 5,689,035.

Genes that Confer Resistance to an Herbicide

An herbicide that inhibits the growing point or meristem, such as animidazolinone or a sulfonylurea: See, for example, exemplary genes inthis category that code for mutant ALS and AHAS enzyme as described byLee et al., EMBO J. 7:1241 (1988), and Miki et al., Theor. Appl. Genet.80:449 (1990), respectively.

Glyphosate (resistance conferred by mutant5-enolpyruvlshikimate-3-phosphate synthase (EPSPS) and aroA genes,respectively) and other phosphono compounds such as glufosinate(phosphinothricin acetyl transferase (PAT) and Streptomyceshygroscopicus PAT bar genes), and pyridinoxy or phenoxy proprionic acidsand cyclohexanediones (ACCase inhibitor-encoding genes): See, forexample, U.S. Pat. No. 4,940,835 to Shah, et al., which discloses thenucleotide sequence of a form of EPSPS which can confer glyphosateresistance. U.S. Pat. No. 5,627,061 to Barry et al. also describes genesencoding EPSPS enzymes. See also U.S. Pat. Nos. 6,566,587; 6,338,961;6,248,876 B1; 6,040,497; 5,804,425; 5,633,435; 5,145,783; 4,971,908;5,312,910; 5,188,642; 4,940,835; 5,866,775; 6,225,114 B1; 6,130,366;5,310,667; 4,535,060; 4,769,061; 5,633,448; 5,510,471; Re. 36,449; RE37,287 E; and U.S. Pat. No. 5,491,288; and international publicationsEP1173580; WO 01/66704; EP1173581 and EP1173582. Glyphosate resistanceis also imparted to plants that express a gene that encodes a glyphosateoxido-reductase enzyme as described more fully in U.S. Pat. Nos.5,776,760 and 5,463,175. In addition glyphosate resistance can beimparted to plants by the over expression of genes encoding glyphosateN-acetyltransferase. See, for example, U.S. application Ser. No.10/427,692. A DNA molecule encoding a mutant aroA gene can be obtainedunder ATCC accession number 39256, and the nucleotide sequence of themutant gene is disclosed in U.S. Pat. No. 4,769,061 to Comai. Europeanpatent application No. 0 333 033 to Kumada et al., and U.S. Pat. No.4,975,374 to Goodman et al., disclose nucleotide sequences of glutaminesynthetase genes which confer resistance to herbicides such asL-phosphinothricin. The nucleotide sequence of a PAT gene is provided inEuropean application No. 0 242 246 to Leemans et al. DeGreef et al.,Bio/Technology 7:61 (1989) describe the production of transgenic plantsthat express chimeric bar genes coding for phosphinothricin acetyltransferase activity. Exemplary of genes conferring resistance tophenoxy proprionic acids and cyclohexones, such as sethoxydim andhaloxyfop are the Acc1-S1, Acc1-S2, and Acc2-S3 genes described byMarshall et al., Theor. Appl Genet. 83:435 (1992).

An herbicide that inhibits photosynthesis, such as a triazine (psbA andgs+ genes) and a benzonitrile (nitrilase gene): See, for example,Przibila et al., Plant Cell 3:169 (1991), describe the transformation ofChlamydomonas with plasmids encoding mutant psbA genes. Nucleotidesequences for nitrilase genes are disclosed in U.S. Pat. No. 4,810,648to Stalker and DNA molecules containing these genes are available underATCC Accession Nos. 53435, 67441 and 67442. Cloning and expression ofDNA coding for a glutathione S-transferase is described by Hayes et al.,Biochem. J. 285:173 (1992).

Acetohydroxy acid synthase, which has been found to make plants thatexpress this enzyme resistant to multiple types of herbicides, has beenintroduced into a variety of plants. See, for example, Hattori et al.,Mol. Gen. Genet. 246:419, 1995. Other genes that confer tolerance toherbicides include a gene encoding a chimeric protein of rat cytochromeP4507A1 and yeast NADPH-cytochrome P450 oxidoreductase (Shiota et al.,Plant Physiol., 106:17, 1994), genes for glutathione reductase andsuperoxide dismutase (Aono et al., Plant Cell Physiol. 36:1687, 1995),and genes for various phosphotransferases (Datta et al., Plant Mol.Biol. 20:619, 1992).

Protoporphyrinogen oxidase (protox) is necessary for the production ofchlorophyll. The protox enzyme serves as the target for a variety ofherbicidal compounds. These herbicides also inhibit growth of differentspecies of plants present. The development of plants containing alteredprotox activity which are resistant to these herbicides are describedin, for example, U.S. Pat. Nos. 6,288,306; 6,282,837; 5,767,373; andinternational publication WO 01/12825.

Genes that Confer or Contribute to a Value-Added Trait

Modified fatty acid metabolism, for example, by transforming a plantwith an antisense gene of stearyl-ACP desaturase to increase stearicacid content of the plant. See, for example, Knultzon et al., Proc.Natl. Acad. Sci. USA 89:2625 (1992).

Decreased phytate content: 1) Introduction of a phytase-encoding geneenhances breakdown of phytate, adding more free phosphate to thetransformed plant. For example, see Van Hartingsveldt et al., Gene127:87 (1993), for a disclosure of the nucleotide sequence of anAspergillus niger phytase gene. 2) Up-regulation of a gene that reducesphytate content. This, for example, could be accomplished by cloning andthen re-introducing DNA associated with one or more of the alleles, suchas the LPA alleles, identified in maize mutants characterized by lowlevels of phytic acid, such as in Raboy et al., Maydica 35: 383 (1990)and/or by altering inositol kinase activity as in WO 02/059324,US2003/0009011, WO 03/027243, US2003/0079247, WO 99/05298, U.S. Pat. No.6,197,561, U.S. Pat. No. 6,291,224, U.S. Pat. No. 6,391,348, WO2002/059324, U.S. Pat. No. 2003/0079247, WO98/45448, WO99/55882,WO01/04147.

Impacting carbohydrate compositions by, for example, transforming plantswith a gene coding for an enzyme that alters the branching pattern ofstarch, or a gene altering thioredoxin such as NTR and/or TRX (See U.S.Pat. No. 6,531,648) and/or a gamma zein knock out or mutant such as cs27or TUSC27 or en27 (See U.S. Pat. No. 6,858,778 and US2005/0160488,US2005/0204418). See Shiroza et al., J. Bacteriol. 170: 810 (1988)(nucleotide sequence of Streptococcus mutans fructosyltransferase gene),Steinmetz et al., Mol. Gen. Genet. 200: 220 (1985) (nucleotide sequenceof Bacillus subtilis levansucrase gene), Pen et al., Bio/Technology 10:292 (1992) (production of transgenic plants that express Bacilluslicheniformis alpha-amylase), Elliot et al., Plant Molec. Biol. 21: 515(1993) (nucleotide sequences of tomato invertase genes), Sogaard et al.,J. Biol. Chem. 268: 22480 (1993) (site-directed mutagenesis of barleyalpha-amylase gene), and Fisher et al., Plant Physiol. 102: 1045 (1993)(maize endosperm starch branching enzyme II), WO 99/10498 (improveddigestibility and/or starch extraction through modification ofUDP-D-xylose 4-epimerase, Fragile 1 and 2, Ref 1, HCHL, C4H), U.S. Pat.No. 6,232,529 (method of producing high oil seed by modification ofstarch levels (AGP)). The fatty acid modification genes mentioned abovemay also be used to affect starch content and/or composition through theinterrelationship of the starch and oil pathways.

Altered antioxidant content or composition, such as alteration oftocopherol or tocotrienols: For example, see U.S. Pat. Nos. 6,787,683and 7,154,029 and WO 00/68393 involving the manipulation of antioxidantlevels through alteration of a phytl prenyl transferase (ppt), WO03/082899 through alteration of a homogentisate geranyl transferase(hggt).

Genes that Control Male Sterility

There are several methods of conferring genetic male sterilityavailable, such as multiple mutant genes at separate locations withinthe genome that confer male sterility, as disclosed in U.S. Pat. Nos.4,654,465 and 4,727,219 to Brar et al. and chromosomal translocations asdescribed by Patterson in U.S. Pat. Nos. 3,861,709 and 3,710,511. Inaddition to these methods, Albertsen et al., U.S. Pat. No. 5,432,068,describe a system of nuclear male sterility which includes: identifyinga gene which is critical to male fertility; silencing this native genewhich is critical to male fertility; removing the native promoter fromthe essential male fertility gene and replacing it with an induciblepromoter; inserting this genetically engineered gene back into theplant; and thus creating a plant that is male sterile because theinducible promoter is not “on” resulting in the male fertility gene notbeing transcribed. Fertility is restored by inducing, or turning “on”,the promoter, which in turn allows the gene that confers male fertilityto be transcribed.

Introduction of a deacetylase gene under the control of atapetum-specific promoter and with the application of the chemicalN—Ac-PPT: See, for example, international publication WO 01/29237.

Introduction of various stamen-specific promoters: See, for example,international publications WO 92/13956 and WO 92/13957.

Introduction of the barnase and the barstar genes: See, for example,Paul et al., Plant Mol. Biol. 19:611-622, 1992).

For additional examples of nuclear male and female sterility systems andgenes, see also, U.S. Pat. No. 5,859,341; U.S. Pat. No. 6,297,426; U.S.Pat. No. 5,478,369; U.S. Pat. No. 5,824,524; U.S. Pat. No. 5,850,014;and U.S. Pat. No. 6,265,640.

Genes that Create a Site for Site Specific DNA Integration

Genes that confer resistance to Brown Stem Rot: See, for example, thosedescribed in U.S. Pat. No. 5,689,035. Introduction of FRT sites that maybe used in the FLP/FRT system and/or Lox sites that may be used in theCre/Loxp system for site-specific DNA integration. For example, seeLyznik, et al., Site-Specific Recombination for Genetic Engineering inPlants, Plant Cell Rep (2003) 21:925-932 and WO 99/25821. Other systemsthat may be used include the Gin recombinase of phage Mu (Maeser et al.,1991; Vicki Chandler, The Maize Handbook ch. 118 (Springer-Verlag 1994),the Pin recombinase of E. coli (Enomoto et al., 1983), and the R/RSsystem of the pSR1 plasmid (Araki et al., 1992).

Genes that Affect Abiotic Stress Resistance

Genes that affect abiotic stress resistance (including, for example,flowering and fruit development, drought resistance or tolerance, coldresistance or tolerance, and salt resistance or tolerance) and increasedyield under stress: For example, see: WO 00/73475 where water useefficiency is altered through alteration of malate; U.S. Pat. No.5,892,009, U.S. Pat. No. 5,965,705, U.S. Pat. No. 5,929,305, U.S. Pat.No. 5,891,859, U.S. Pat. No. 6,417,428, U.S. Pat. No. 6,664,446, U.S.Pat. No. 6,706,866, U.S. Pat. No. 6,717,034, U.S. Pat. No. 6,801,104, WO2000/060089, WO 2001/026459, WO 2001/035725, WO 2001/034726, WO2001/035727, WO 2001/036444, WO 2001/036597, WO 2001/036598, WO2002/015675, WO 2002/017430, WO 2002/077185, WO 2002/079403, WO2003/013227, WO 2003/013228, WO 2003/014327, WO 2004/031349, WO2004/076638, WO 98/09521, and WO 99/38977 describing genes, includingCBF genes and transcription factors effective in mitigating the negativeeffects of freezing, high salinity, and drought on plants, as well asconferring other desirable traits; US 2004/0148654 and WO 01/36596 whereabscisic acid is altered in plants resulting in improved plant phenotypesuch as increased yield and/or increased tolerance to abiotic stress; WO2000/006341, WO 04/090143, U.S. application Ser. No. 10/817,483 and U.S.Pat. No. 6,992,237 where cytokinin expression is modified resulting inplants with increased stress tolerance, such as drought tolerance,and/or increased yield. Also see WO 02/02776, WO 2003/052063,JP2002281975, U.S. Pat. No. 6,084,153, WO 01/64898, U.S. Pat. Nos.6,177,275 and 6,107,547 (enhancement of nitrogen utilization and alterednitrogen responsiveness). For ethylene alteration, see US 20040128719,US 20030166197 and WO 2000/32761. For plant transcription factors ortranscriptional regulators of abiotic stress, see e.g. US 20040098764 orUS 20040078852.

Other genes and transcription factors that affect plant growth and othertraits, such as yield, flowering, plant growth and/or plant structure,can be introduced or introgressed into plants. See, for example, WO97/49811 (LHY), WO 98/56918 (ESD4), WO 97/10339 and U.S. Pat. No.6,573,430 (TFL), U.S. Pat. No. 6,713,663 (FT), WO 96/14414 (CON), WO96/38560, WO 01/21822 (VRN1), WO 00/44918 (VRN2), WO 99/49064 (GI), WO00/46358 (FRI), WO 97/29,123 U.S. Pat. No. 6,794,560, U.S. Pat. No.6,307,126 (GAI), WO 99/09174 (D8 and Rht), and WO 2004/076638 and WO2004/031349 (transcription factors).

Methods for Transformation of Tomato Plants of Tomato Rootstock Variety‘RTS-123’

Numerous methods for plant transformation have been developed includingbiological and physical plant transformation protocols. See, forexample, Miki et al., “Procedures for Introducing Foreign DNA intoPlants” in Methods in Plant Molecular Biology and Biotechnology, Glick,B. R. and Thompson, J. E. Eds. (CRC Press, Inc. Boca Raton, 1993) pages67-88. In addition, expression vectors and in-vitro culture methods forplant cell or tissue transformation and regeneration of plants areavailable. See, for example, Gruber et al., “Vectors for PlantTransformation” in Methods in Plant Molecular Biology and Biotechnology,Glick, B. R. and Thompson, J. E. Eds. (CRC Press, Inc., Boca Raton,1993) pages 89-119.

Agrobacterium-mediated Transformation: One method for introducing anexpression vector into plants is based on the natural transformationsystem of Agrobacterium. See, for example, Horsch et al., Science227:1229 (1985). A. tumefaciens and A. rhizogenes are plant pathogenicsoil bacteria which genetically transform plant cells. The Ti and Riplasmids of A. tumefaciens and A. rhizogenes, respectively, carry genesresponsible for genetic transformation of the plant. See, for example,Kado, C. I., Crit. Rev. Plant Sci. 10:1 (1991). Descriptions ofAgrobacterium vector systems and methods for Agrobacterium-mediated genetransfer are provided by Gruber et al., supra, Miki et al., supra andMoloney et al., Plant Cell Reports 8:238 (1989). See also, U.S. Pat. No.5,563,055 (Townsend and Thomas), issued Oct. 8, 1996.

Direct Gene Transfer: Alternatives to Agrobacterium-mediatedtransformation exist such as, for example, direct gene transfer. Agenerally applicable method of plant transformation ismicroprojectile-mediated transformation where DNA is carried on thesurface of microprojectiles measuring 1 to 4 μm. The expression vectoris introduced into plant tissues with a biolistic device thataccelerates the microprojectiles to speeds of 300 to 600 m/s which issufficient to penetrate plant cell walls and membranes. Sanford et al.,Part. Sci. Technol. 5:27 (1987); Sanford, J. C., Trends Biotech. 6:299(1988); Klein et al., Bio/Tech. 6:559-563 (1988); Sanford, J. C. PhysiolPlant 7:206 (1990); Klein et al., Biotechnology 10:268 (1992). See alsoU.S. Pat. No. 5,015,580 (Christou et al.), issued May 14, 1991 and U.S.Pat. No. 5,322,783 (Tomes, et al.), issued Jun. 21, 1994.

Another method for physical delivery of DNA to plants is sonication oftarget cells. See, for example, Zhang et al., Bio/Technology 9:996(1991). Alternatively, liposome and spheroplast fusion have been used tointroduce expression vectors into plants. Deshayes et al., EMBO J.,4:2731 (1985); Christou et al., Proc Natl. Acad. Sci. USA 84:3962(1987). Direct uptake of DNA into protoplasts using CaCl2 precipitation,polyvinyl alcohol or poly-L-ornithine has also been reported. Hain etal., Mol. Gen. Genet. 199:161 (1985) and Draper et al., Plant CellPhysiol. 23:451 (1982). Electroporation of protoplasts and whole cellsand tissues have also been described (Donn et al., In Abstracts of VIIthInternational Congress on Plant Cell and Tissue Culture IAPTC, A2-38, p53 (1990); D'Halluin et al., Plant Cell 4:1495-1505 (1992) and Spenceret al., Plant Mol. Biol. 24:51-61 (1994)).

Following transformation of target tomato tissues, expression of theabove-described selectable marker genes allows for preferentialselection of transformed cells, tissues and/or plants, usingregeneration and selection methods well known in the art.

The foregoing methods for transformation may be used for producing atransgenic variety are merely exemplary. One of skill in the art mayrecognize additional transformation techniques that may be used toproduce new tomato varieties described herein. A transgenic variety maybe crossed with another (non-transformed or transformed) variety inorder to produce a new transgenic variety. Alternatively, a genetictrait that has been engineered into a particular tomato line could bemoved into another line using traditional backcrossing techniques thatare well known in the plant breeding arts. For example, a backcrossingapproach could be used to move an engineered trait from a public varietyinto a desirable hybrid, or from a variety containing a foreign gene inits genome into a variety or varieties that do not contain that gene. Asused herein, “crossing” can refer to a simple X by Y cross or theprocess of backcrossing, depending on the context.

Genetic Marker Profile Through SSR and First Generation Progeny

In addition to phenotypic observations, a plant, for example a plant oftomato rootstock variety ‘RTS-123’, can also be identified by itsgenotype. The genotype of a plant can be characterized through a geneticmarker profile which can identify plants of the same variety or arelated variety or be used to determine or validate a pedigree. Geneticmarker profiles can be obtained by techniques such as RestrictionFragment Length Polymorphisms (RFLPs), Randomly Amplified PolymorphicDNAs (RAPDs), Arbitrarily Primed Polymerase Chain Reaction (AP-PCR), DNAAmplification Fingerprinting (DAF), Sequence Characterized AmplifiedRegions (SCARs), Amplified Fragment Length Polymorphisms (AFLPs), SimpleSequence Repeats (SSRs) which are also referred to as Microsatellites,and Single Nucleotide Polymorphisms (SNPs). For example, see Cregan et.al, “An Integrated Genetic Linkage Map of the Soybean Genome” CropScience 39:1464-1490 (1999), and Berry et al., Assessing Probability ofAncestry Using Simple Sequence Repeat Profiles: Applications to MaizeInbred Lines and Soybean Varieties” Genetics 165:331-342 (2003).

Particular markers used for these purposes may include any type ofmarker and marker profile which provides a means of distinguishingvarieties. One method of comparison is to use only homozygous loci for atomato plant of tomato rootstock variety ‘RTS-123’.

Primers and PCR protocols for assaying these and other markers are knownin the art and may be adapted from those disclosed in the Soybase(sponsored by the USDA Agricultural Research Service and Iowa StateUniversity). In addition to being used for identification of tomatoplants of tomato rootstock variety ‘RTS-123’ and plant parts and plantcells of tomato plants of tomato rootstock variety ‘RTS-123’, thegenetic profile may be used to identify a tomato plant produced throughthe use of a tomato plant of tomato rootstock variety ‘RTS-123’ or toverify a pedigree for progeny plants produced through the use of atomato plant of tomato rootstock variety ‘RTS-123’. The presentdisclosure relates to a tomato variety characterized by molecular andphysiological data obtained from the representative sample of saidvariety deposited with the American Type Culture Collection (ATCC).Further provided by the disclosure is a tomato plant formed by thecombination of one of the disclosed tomato plants or plant cells withanother tomato plant or cell and containing the homozygous alleles ofthe variety.

Means of performing genetic marker profiles using SSR polymorphisms arewell known in the art. SSRs are genetic markers based on polymorphismsin repeated nucleotide sequences, such as microsatellites. A markersystem based on SSRs can be informative in linkage analysis relative toother marker systems in that multiple alleles may be present. Anotheradvantage of this type of marker is that, through use of flankingprimers, detection of SSRs can be achieved, for example, by thepolymerase chain reaction (PCR). The PCR detection involves the use oftwo oligonucleotide primers flanking the polymorphic segment ofrepetitive DNA, repeated cycles of heat denaturation of the DNA followedby primer annealing to complementary sequences at low temperatures, andextension of the annealed primers with DNA polymerase. Followingamplification, markers can be scored by electrophoresis of theamplification products. Scoring of marker genotype is based on the sizeof the amplified fragment, which may be measured by the number of basepairs of the fragment.

The SSR profile of tomato variety such as a tomato plant of tomatorootstock variety ‘RTS-123’ can be used to identify tomato plants havingthat tomato variety as a parent, since such progeny tomato plants willcontain the same homozygous alleles as the parent. For tomato varietiesthat are essentially homozygous at all relevant loci, most loci shouldhave only one type of allele present. In contrast, a genetic markerprofile of an F1 progeny should be the sum of those parents, e.g., ifone parent was homozygous for allele x at a particular locus, and theother parent homozygous for allele y at that locus, then the F1 progenywill be xy (heterozygous) at that locus. Subsequent generations ofprogeny produced by selection and breeding are expected to be ofgenotype x (homozygous), y (homozygous), or xy (heterozygous) for thatlocus position. When the F1 plant is selfed or sibbed for successivefilial generations, the locus should be either x or y for that position.

In addition, plants and plant parts substantially benefiting from theuse of a tomato plant of tomato rootstock variety ‘RTS-123’ containing abackcross conversion, transgene, or genetic sterility factor, may beidentified by having a molecular marker profile with a high percentidentity to a tomato plant of tomato rootstock variety ‘RTS-123’ used intheir development. Such a percent identity might be 95%, 96%, 97%, 98%,99%, 99.5% or 99.9% identical to a tomato plant of tomato rootstockvariety ‘RTS-123’ used to develop the plant and/or plant part.

The SSR profile of a tomato plant of tomato rootstock variety ‘RTS-123’can also be used to identify essentially derived varieties and otherprogeny varieties developed from the use of a tomato plant of tomatorootstock variety ‘RTS-123’, as well as cells and other plant partsthereof. Such plants may be developed using the markers identified in WO00/31964, U.S. Pat. No. 6,162,967 and U.S. application Ser. No.09/954,773. Progeny plants and plant parts produced using the a tomatoplant of tomato rootstock variety ‘RTS-123’ may be identified by havinga molecular marker profile of at least 25%, 30%, 35%, 40%, 45%, 50%,55%, 60%, 65%, 70%, 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%,85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%,99% or 99.5% genetic contribution from a tomato plant of tomatorootstock variety ‘RTS-123’, as measured by either percent identity orpercent similarity. Such progeny may be further characterized as beingwithin a pedigree distance of respective tomato plant, such as within 1,2, 3, 4 or 5 or less cross-pollinations to a tomato plant other than atomato plant of tomato rootstock variety ‘RTS-123’ or a plant that has atomato plant of tomato rootstock variety ‘RTS-123’, as a progenitor.Unique molecular profiles may be identified with other molecular toolssuch as SNPs and RFLPs.

While determining the SSR genetic marker profile of the plants describedsupra, several unique SSR profiles may also be identified which did notappear in either parent of such plant. Such unique SSR profiles mayarise during the breeding process from recombination or mutation. Acombination of several unique alleles provides a means of identifying aplant variety, an F1 progeny produced from such variety, and progenyproduced from such variety.

Single-Gene Conversions

When the term “tomato plant” is used in the context of the presentdisclosure, this also includes any single gene conversions of the tomatorootstock variety ‘RTS-123’. The term single gene converted plant asused herein refers to those tomato plants which are developed by a plantbreeding technique called backcrossing wherein essentially all of thedesired morphological and physiological characteristics of a variety arerecovered in addition to the single gene transferred into the varietyvia the backcrossing technique. Backcrossing methods can be used withthe present disclosure to improve or introduce a characteristic into thevariety. The term “backcrossing” as used herein refers to the repeatedcrossing of a hybrid progeny back to the recurrent parent, i.e.,backcrossing 1, 2, 3, 4, 5, 6, 7, 8 or more times to the recurrentparent. The parental tomato plant that contributes the gene for thedesired characteristic is termed the nonrecurrent or donor parent. Thisterminology refers to the fact that the nonrecurrent parent is used onetime in the backcross protocol and therefore does not recur. Theparental tomato plant to which the gene or genes from the nonrecurrentparent are transferred is known as the recurrent parent as it is usedfor several rounds in the backcrossing protocol (Poehlman & Sleper,1994; Fehr, Principles of Cultivar Development pp. 261-286 (1987)). In atypical backcross protocol, the original variety of interest (recurrentparent) is crossed to a second variety (nonrecurrent parent) thatcarries the single gene of interest to be transferred. The resultingprogeny from this cross are then crossed again to the recurrent parentand the process is repeated until a tomato plant is obtained whereinessentially all of the desired morphological and physiologicalcharacteristics of the recurrent parent are recovered in the convertedplant, in addition to the single transferred gene from the nonrecurrentparent.

The selection of a suitable recurrent parent is an important step for asuccessful backcrossing procedure. The goal of a backcross protocol isto alter or substitute a single trait or characteristic in the originalvariety. To accomplish this, a single gene of the recurrent variety ismodified or substituted with the desired gene from the nonrecurrentparent, while retaining essentially all of the rest of the desiredgenetic, and therefore the desired physiological and morphological,constitution of the original variety. The choice of the particularnonrecurrent parent will depend on the purpose of the backcross; one ofthe major purposes is to add an agronomically important trait to theplant. The exact backcrossing protocol will depend on the characteristicor trait being altered to determine an appropriate testing protocol.Although backcrossing methods are simplified when the characteristicbeing transferred is a dominant allele, a recessive allele may also betransferred. In this instance it may be necessary to introduce a test ofthe progeny to determine if the desired characteristic has beensuccessfully transferred.

Many single gene traits have been identified that are not regularlyselected for in the development of a new variety but that can beimproved by backcrossing techniques. Single gene traits may or may notbe transgenic; examples of these traits include, for example, malesterility, herbicide resistance, resistance for bacterial, fungal, orviral disease, insect resistance, male fertility, enhanced nutritionalquality, industrial usage, yield stability and yield enhancement. Thesegenes are generally inherited through the nucleus. Several of thesesingle gene traits are described in U.S. Pat. Nos. 5,959,185; 5,973,234and 5,977,445.

Tissue Culture

Further reproduction of tomato rootstock variety ‘RTS-123’ can occur bytissue culture and regeneration. Tissue culture of various tissues oftomatoes and regeneration of plants therefrom is well known and widelypublished. For example, reference may be had to Girish-Chandel et al.,Advances in Plant Sciences, 2000, 13: 1, 11-17; Costa et al., Plant CellReport, 2000, 19: 3 327-332; Plastira et al., Acta Horticulturae, 1997,447, 231-234; Zagorska et al., Plant Cell Report, 1998, 17: 12 968-973;Asahura et al., Breeding Science, 1995, 45: 455-459; Chen et al.,Breeding Science, 1994, 44: 3, 257-262, Patil et al., Plant and Tissueand Organ Culture, 1994, 36: 2, 255-258; Gill, R., et al., SomaticEmbryogenesis and Plant Regeneration from Seedling Cultures of Tomato(Lycopersicon esculentum Mill.), J. Plant Physiol., 147:273-276 (1995);Jose M. Segui-Simarro and Fernando Nuez, Embryogenesis induction,callogenesis, and plant regeneration by in vitro culture of tomatoisolated microspores and whole anthers J. Exp. Bot., March 2007; 58:1119-1132; Hamza et al., Re-evaluation of Conditions for PlantRegeneration and Agrobacterium-Mediated Transformation from Tomato(Lycopersicon esculentum), J. Exp. Bot., December 1993; 44: 1837-1845.Thus, another aspect of this disclosure is to provide cells which upongrowth and differentiation produce tomato plants having thephysiological and morphological characteristics of a tomato plant oftomato rootstock variety ‘RTS-123’.

As used herein, the term “tissue culture” indicates a compositioncontaining isolated cells of the same or a different type or acollection of such cells organized into parts of a plant. Exemplarytypes of tissue cultures are protoplasts, calli, plant clumps, and plantcells that can generate tissue culture that are intact in plants orparts of plants, such as embryos, pollen, flowers, seeds, fruit,petioles, leaves, stems, roots, root tips, anthers, pistils and thelike. Means for preparing and maintaining plant tissue culture are wellknown in the art. By way of example, a tissue culture containing organshas been used to produce regenerated plants. U.S. Pat. Nos. 5,959,185;5,973,234 and 5,977,445 describe certain techniques.

Vegetative Propagation

Tomato plants can also be propagated vegetatively. Accordingly, thepresent disclosure is further directed to vegetative propagation of atomato plant of tomato rootstock variety ‘RTS-123’. A part of the plant,for example a shoot tissue, is collected and a new plant is obtainedfrom the part. Such part typically includes an apical meristem of theplant. The collected part is transferred to a medium allowingdevelopment of a plantlet including, for example, rooting or developmentof shoots, or is grafted onto a tomato plant or a rootstock prepared tosupport growth of shoot tissue. This is achieved using methodswell-known in the art. Accordingly, in one embodiment, a method ofvegetatively propagating a tomato plant of the present disclosureinvolves collecting a part of a plant according to the presentdisclosure, e.g. a shoot tissue, and obtaining a plantlet from saidpart. In one embodiment, a method of vegetatively propagating a tomatoplant of the present disclosure involves: a) collecting tissue of aplant of the present disclosure; and b) rooting said proliferated shootsto obtain rooted plantlets. In one embodiment, a method of vegetativelypropagating a plant of the present disclosure involves: a) collectingtissue of a plant of the present disclosure; b) cultivating said tissueto obtain proliferated shoots; and c) rooting said proliferated shootsto obtain rooted plantlets. In one embodiment, such methods furtherinvolve growing a plant from said plantlets. In one embodiment, a fruitis harvested from said plant.

Additional Breeding Methods

Tomato varieties, such as tomato rootstock variety ‘RTS-123’, aretypically developed for use as fresh produce or for processing. However,tomato varieties also provide a source of breeding material that may beused to develop new tomato varieties. Plant breeding techniques known inthe art and used in a tomato plant breeding program may include, forexample, chasing selfs, recurrent selection, mass selection, bulkselection, mutation breeding, backcrossing, pedigree breeding, openpollination breeding, restriction fragment length polymorphism enhancedselection, genetic marker enhanced selection, making double haploids,and transformation. Often combinations of these techniques are used. Thedevelopment of tomato varieties in a plant breeding program involves, ingeneral, the development and evaluation of homozygous varieties. Thereare many analytical methods available to evaluate a new variety. Theoldest and most traditional method of analysis is the observation ofphenotypic traits but genotypic analysis may also be used. Thus, anotheraspect of the disclosure is to provide a tomato plant of the tomatorootstock variety ‘RTS-123’ as a source of breeding material for thedevelopment of new tomato varieties using, for example, the breedingtechniques described herein. One of skill in the art would recognizethat additional breeding techniques may exist and may be used to developnew tomato varieties using plants of the tomato rootstock variety‘RTS-123’.

The present disclosure is directed to methods for producing a tomatoplant by crossing a first parent tomato plant with a second parenttomato plant where either the first or second parent tomato plant is atomato plant of tomato rootstock variety ‘RTS-123’. The other parent maybe any other tomato plant, such as a tomato plant that is part of asynthetic or natural population. Any such methods using a tomato plantof tomato rootstock variety ‘RTS-123’ are part of this disclosure:selfing, sibbing, backcrosses, mass selection, pedigree breeding, bulkselection, hybrid production, crosses to populations, and the like.These methods are well known in the art and some of the more commonlyused breeding methods are described herein. Descriptions of breedingmethods can be found in one of several reference books (e.g., Allard,Principles of Plant Breeding, 1960; Simmonds, Principles of CropImprovement, 1979; Sneep et al., 1979; Fehr, “Breeding Methods forCultivar Development,” 2.sup.nd ed., Wilcox editor, 1987).

The following describes breeding methods that may be used with tomatoplants of the tomato rootstock variety ‘RTS-123’ in the development offurther tomato plants. One such embodiment is a method for developing aprogeny tomato plant of tomato rootstock variety ‘RTS-123’ in a tomatoplant breeding program involving: obtaining the tomato plant, or a partthereof, of tomato rootstock variety ‘RTS-123’, utilizing said plant orplant part as a source of breeding material, and selecting a progenyplant of tomato rootstock variety ‘RTS-123’ with molecular markers incommon with tomato rootstock variety ‘RTS-123’ and/or with morphologicaland/or physiological characteristics selected from the characteristicsdisclosed herein in the section entitled “Characterization of TomatoRootstock Variety ‘RTS-123’.” Breeding steps that may be used in thetomato plant breeding programs may include pedigree breeding,backcrossing, mutation breeding, and recurrent selection. In conjunctionwith these steps, techniques such as RFLP-enhanced selection, geneticmarker enhanced selection (for example SSR markers) and the making ofdouble haploids may be utilized.

Another method involves producing a population of tomato rootstockvariety ‘RTS-123’ progeny tomato plants, involving crossing a tomatoplant of tomato rootstock variety ‘RTS-123’ with another tomato plant,thereby producing a population of tomato plants, which, on average,derive 50% of their alleles from a tomato plant of tomato rootstockvariety ‘RTS-123’. A plant of this population may be selected andrepeatedly selfed or sibbed with a tomato cultivar resulting from thesesuccessive filial generations. In one embodiment, the tomato cultivarproduced by this method has obtained at least 50% of its alleles from atomato plant of tomato rootstock variety ‘RTS-123’.

One of ordinary skill in the art of plant breeding would know how toevaluate the traits of two plant varieties to determine if there is nosignificant difference between the two traits expressed by thosevarieties. For example, see Fehr and Walt, Principles of CultivarDevelopment, p 261-286 (1987). Thus, the disclosure includes ‘RTS-123’progeny tomato plants containing a combination of at least two traits ofa tomato plant of tomato rootstock variety ‘RTS-123’, the traits beingselected from those listed in the section entitled “Characterization ofTomato Rootstock Variety ‘RTS-123’,” so that the progeny tomato plant isnot significantly different for the traits than a tomato plant of tomatorootstock variety ‘RTS-123’ as determined at the 5% significance levelwhen grown in the same environmental conditions. Using techniquesdescribed herein, molecular markers may be used to identify said progenyplant as a tomato rootstock variety ‘RTS-123’ progeny plant. For each ofthe evaluation schemes involving a tomato plant of tomato rootstockvariety ‘RTS-123’, mean trait values may be used to determine whethertrait differences are significant, and preferably the traits aremeasured on plants grown under the same environmental conditions. Oncesuch a variety is developed its value is substantial since it isimportant to advance the germplasm base as a whole in order to maintainor improve traits such as yield, disease resistance, pest resistance,and plant performance in extreme environmental conditions.

Progeny of a tomato plant of tomato rootstock variety ‘RTS-123’ may alsobe characterized through their filial relationship with a tomato plantof tomato rootstock variety ‘RTS-123’, as for example being within acertain number of breeding crosses to a tomato plant of tomato rootstockvariety ‘RTS-123’. A breeding cross is a cross made to introduce newgenetics into the progeny, and is distinguished from a cross, such as aself or a sib cross, made to select among existing genetic alleles. Thelower the number of breeding crosses in the pedigree, the closer therelationship between a tomato plant of tomato rootstock variety‘RTS-123’ and its progeny. For example, progeny produced by the methodsdescribed herein may be within 1, 2, 3, 4 or 5 breeding crosses of atomato plant of tomato rootstock variety ‘RTS-123’

Exemplary breeding techniques are further described herein and may beused in breeding schemes using tomato plants of tomato rootstock variety‘RTS-123’.

Chasing Selfs

Chasing selfs involves identifying inbred plants among tomato plantsthat have been grown from tomato plant seed, such as the seed from aplant of tomato rootstock variety ‘RTS-123’. Once the seed is planted,the inbred plants may be identified and selected due to their decreasedvigor relative to the hybrid plants that grow from the hybrid seed. Bylocating the inbred plants, isolating them from the rest of the plants,and self-pollinating them (i.e., “chasing selfs”), a breeder can obtainan inbred line that is identical to an inbred parent used to produce thehybrid.

Accordingly, another aspect of the present disclosure relates to amethod for producing an inbred tomato variety by: planting seed of atomato plant of tomato rootstock variety ‘RTS-123’; growing plants fromthe seed; identifying one or more inbred tomato plants; controllingpollination in a manner which preserves homozygosity of the one or moreinbred plants; and harvesting resultant seed from the one or more inbredplants. The step of identifying the one or more inbred tomato plants mayfurther include identifying plants with decreased vigor, i.e., plantsthat appear less robust than plants of the tomato rootstock variety‘RTS-123’. Tomato plants capable of expressing essentially all of thephysiological and morphological characteristics of the parental inbredlines of tomato plants of the tomato rootstock variety ‘RTS-123’ includetomato plants obtained by chasing selfs from seed of a tomato plant oftomato rootstock variety ‘RTS-123’.

One of ordinary skill in the art will recognize that once a breeder hasobtained inbred tomato plants by chasing selfs from seed of plants ofthe tomato rootstock variety ‘RTS-123’, the breeder can then produce newinbred plants such as by sib-pollinating, or by crossing one of theidentified inbred tomato plant with a tomato plant of tomato rootstockvariety ‘RTS-123’.

Backcross Conversion

Tomato plants of the tomato rootstock variety ‘RTS-123’ represents a newbase genetic variety into which a new locus or trait may beintrogressed. Backcrossing represents an important method that can beused to accomplish such an introgression. The term backcross conversionand single locus conversion are used interchangeably to designate theproduct of a backcrossing program.

A backcross conversion of a tomato variety such as, for example, tomatorootstock variety ‘RTS-123’, occurs when DNA sequences are introducedthrough backcrossing (Hallauer et al, 1988, “Corn Breeding” Corn andCorn Improvements, No. 18, pp. 463-481), with the tomato varietyutilized as the recurrent parent. Both naturally occurring andtransgenic DNA sequences may be introduced through backcrossingtechniques. A backcross conversion may produce a plant with a trait orlocus conversion in at least two or more backcrosses, including at least2 crosses, at least 3 crosses, at least 4 crosses, at least 5 crossesand the like. Molecular marker assisted breeding or selection may beutilized to reduce the number of backcrosses necessary to achieve thebackcross conversion. For example, see Openshaw, S. J. et al.,Marker-assisted Selection in Backcross Breeding. In: ProceedingsSymposium of the Analysis of Molecular Data, August 1994, Crop ScienceSociety of America, Corvallis, Oreg., where it is demonstrated that abackcross conversion can be made in as few as two backcrosses.

The complexity of the backcross conversion method depends on the type oftrait being transferred (single genes or closely linked genes as vs.unlinked genes), the level of expression of the trait, the type ofinheritance (cytoplasmic or nuclear) and the types of parents includedin the cross. Desired traits that may be transferred through backcrossconversion may include, for example, sterility (nuclear andcytoplasmic), fertility restoration, nutritional enhancements, droughttolerance, nitrogen utilization, industrial enhancements, diseaseresistance (bacterial, fungal or viral), insect resistance and herbicideresistance. In addition, an introgression site itself, such as an FRTsite, Lox site or other site specific integration site, may be insertedby backcrossing and utilized for direct insertion of one or more genesof interest into a specific plant variety. In some embodiments of thedisclosure, the number of loci that may be backcrossed into a tomatovariety such as, for example, tomato rootstock variety ‘RTS-123’, is atleast 1, 2, 3, 4, or 5 and/or no more than 6, 5, 4, 3, or 2. A singlelocus may contain several transgenes, such as a transgene for diseaseresistance that, in the same expression vector, also contains atransgene for herbicide resistance. The gene for herbicide resistancemay be used as a selectable marker and/or as a phenotypic trait. Asingle locus conversion of site specific integration system allows forthe integration of multiple genes at the converted loci.

The backcross conversion may result from either the transfer of adominant allele or a recessive allele. Selection of progeny containingthe trait of interest is accomplished by direct selection for a traitassociated with a dominant allele. Transgenes transferred viabackcrossing typically function as a dominant single gene trait and arerelatively easy to classify. Selection of progeny for a trait that istransferred via a recessive allele involves growing and selfing thefirst backcross generation to determine which plants carry the recessivealleles. Recessive traits may involve additional progeny testing insuccessive backcross generations to determine the presence of the locusof interest. The last backcross generation is usually selfed to givepure breeding progeny for the gene(s) being transferred, although abackcross conversion with a stably introgressed trait may also bemaintained by further backcrossing to the recurrent parent withselection for the converted trait.

Along with selection for the trait of interest, progeny are selected forthe phenotype of the recurrent parent. The backcross is a form ofinbreeding, and the features of the recurrent parent are automaticallyrecovered after successive backcrosses. Poehlman, Breeding Field Crops,P. 204 (1987). Poehlman suggests from one to four or more backcrosses,but as noted above, the number of backcrosses necessary can be reducedwith the use of molecular markers. Other factors, such as a geneticallysimilar donor parent, may also reduce the number of backcrossesnecessary. As noted by Poehlman, backcrossing is easiest for simplyinherited, dominant and easily recognized traits.

Pedigree Breeding

Pedigree breeding starts with the crossing of two genotypes, such astomato rootstock variety ‘RTS-123’ and another tomato variety having oneor more desirable characteristics that is lacking or which complementstomato rootstock variety ‘RTS-123’. If the two original parents do notprovide all the desired characteristics, other sources can be includedin the breeding population. In the pedigree method, superior plants areselfed and selected in successive filial generations. In the succeedingfilial generations the heterozygous condition gives way to homogeneousvarieties as a result of self-pollination and selection. Typically inthe pedigree method of breeding, five or more successive filialgenerations of selfing and selection is practiced: F1 to F2; F2 to F3;F3 to F4; F4 to F5, etc. After a sufficient amount of inbreeding,successive filial generations will serve to increase seed of thedeveloped variety. Preferably, the developed variety contains homozygousalleles at about 95% or more of its loci.

In addition to being used to create a backcross conversion, backcrossingcan also be used in combination with pedigree breeding. As discussedpreviously, backcrossing can be used to transfer one or morespecifically desirable traits from one variety, the donor parent, to adeveloped variety called the recurrent parent, which has overall goodcharacteristics yet lacks that desirable trait or traits. However, thesame procedure can be used to move the progeny toward the genotype ofthe recurrent parent but at the same time retain many components of thenon-recurrent parent by stopping the backcrossing at an early stage andproceeding with selfing and selection. For example, a tomato variety maybe crossed with another variety to produce a first generation progenyplant. The first generation progeny plant may then be backcrossed to oneof its parent varieties to create a BC1 or BC2. Progeny are selfed andselected so that the newly developed variety has many of the attributesof the recurrent parent and yet several of the desired attributes of thenon-recurrent parent. This approach leverages the value and strengths ofthe recurrent parent for use in new tomato varieties.

Therefore, an embodiment of this disclosure is a method of making abackcross conversion of tomato rootstock variety ‘RTS-123’, involvingthe steps of crossing a plant of tomato rootstock variety ‘RTS-123’ witha donor plant having a desired trait, selecting an F1 progeny planthaving the desired trait, and backcrossing the selected F1 progeny plantto a plant of tomato rootstock variety ‘RTS-123’. This method mayfurther involve the step of obtaining a molecular marker profile oftomato rootstock variety ‘RTS-123’ and using the molecular markerprofile to select for a progeny plant with the desired trait and themolecular marker profile of tomato rootstock variety ‘RTS-123’. In oneembodiment the desired trait is a mutant gene or transgene present inthe donor parent.

Recurrent Selection and Mass Selection

Recurrent selection is a method used in a plant breeding program toimprove a population of plants. The method entails individual plantscross pollinating with each other to form progeny. The progeny are grownand the superior progeny selected by any number of selection methods,which include individual plant, half-sib progeny, full-sib progeny andselfed progeny. The selected progeny are cross pollinated with eachother to form progeny for another population. This population is plantedand again superior plants are selected to cross pollinate with eachother. Recurrent selection is a cyclical process and therefore can berepeated as many times as desired. The objective of recurrent selectionis to improve the traits of a population. The improved population canthen be used as a source of breeding material to obtain new varietiesfor commercial or breeding use, including the production of a syntheticcultivar. A synthetic cultivar is the resultant progeny formed by theintercrossing of several selected varieties.

Mass selection is a useful technique when used in conjunction withmolecular marker enhanced selection. In mass selection, seeds fromindividuals are selected based on phenotype or genotype. These selectedseeds are then bulked and used to grow the next generation. Bulkselection may involve growing a population of plants in a bulk plot,allowing the plants to self-pollinate, harvesting the seed in bulk andthen using a sample of the seed harvested in bulk to plant the nextgeneration. Also, instead of self-pollination, directed pollinationcould be used as part of the breeding program.

Thus, another aspect of the disclosure is the use of tomato plants oftomato rootstock variety ‘RTS-123’ in recurrent selection and/or massselection breeding schemes and may be used to develop new tomatovarieties.

Mutation Breeding

Mutation breeding is another method of introducing new traits intotomato plants of tomato rootstock variety ‘RTS-123’. Mutations thatoccur spontaneously or are artificially induced can be useful sources ofvariability for a plant breeder. The goal of artificial mutagenesis isto increase the rate of mutation for a desired characteristic. Mutationrates can be increased by many different means including, for example,temperature, long-term seed storage, tissue culture conditions,radiation; such as X-rays, Gamma rays (e.g. cobalt 60 or cesium 137),neutrons, (product of nuclear fission by uranium 235 in an atomicreactor), Beta radiation (emitted from radioisotopes such as phosphorus32 or carbon 14), or ultraviolet radiation (preferably from 2500 to 2900nm), or chemical mutagens (such as base analogues (5-bromo-uracil),related compounds (8-ethoxy caffeine), antibiotics (streptonigrin),alkylating agents (sulfur mustards, nitrogen mustards, epoxides,ethylenamines, sulfates, sulfonates, sulfones, lactones), azide,hydroxylamine, nitrous acid, or acridines. Once a desired trait isobserved through mutagenesis the trait may then be incorporated intoexisting germplasm by traditional breeding techniques. Details ofmutation breeding can be found in “Principles of Cultivar Development”Fehr, 1993 Macmillan Publishing Company. In addition, mutations createdin other tomato plants may be used to produce a backcross conversion oftomato plants of tomato rootstock variety ‘RTS-123’ that includes suchmutation.

Breeding with Molecular Markers

Molecular markers, which includes markers identified through the use oftechniques such as Isozyme Electrophoresis, Restriction Fragment LengthPolymorphisms (RFLPs), Randomly Amplified Polymorphic DNAs (RAPDs),Arbitrarily Primed Polymerase Chain Reaction (AP-PCR), DNA AmplificationFingerprinting (DAF), Sequence Characterized Amplified Regions (SCARs),Amplified Fragment Length Polymorphisms (AFLPs), Simple Sequence Repeats(SSRs) and Single Nucleotide Polymorphisms (SNPs), may be used in plantbreeding methods utilizing a tomato plant of tomato rootstock variety‘RTS-123’.

Isozyme Electrophoresis and RFLPs have been widely used to determinegenetic composition. See, for example, Shoemaker and Olsen, ((1993)Molecular Linkage Map of Soybean (Glycine max L. Merr.). p. 6.131-6.138.In S. J. O'Brien (ed.) Genetic Maps: Locus Maps of Complex Genomes. ColdSpring Harbor Laboratory Press. Cold Spring Harbor, N.Y.), developed amolecular genetic linkage map that consisted of 25 linkage groups withabout 365 RFLP, 11 RAPD (random amplified polymorphic DNA), threeclassical markers, and four isozyme loci. See also, Shoemaker R. C. 1994RFLP Map of Soybean. P. 299-309 In R. L. Phillips and I. K. Vasil (ed.)DNA-based markers in plants. Kluwer Academic Press Dordrecht, theNetherlands.

SSR technology is currently the most efficient and practical markertechnology; more marker loci can be routinely used and more alleles permarker locus can be found using SSRs in comparison to RFLPs. For exampleDiwan and Cregan, described a highly polymorphic microsatellite loci intomato with as many as 26 alleles. (Diwan, N., and P. B. Cregan 1997Automated sizing of fluorescent-labeled simple sequence repeat (SSR)markers to assay genetic variation in Soybean Theor. Appl. Genet.95:220-225.) Single Nucleotide Polymorphisms may also be used toidentify the unique genetic composition of the tomato plants describedherein and progeny varieties retaining that unique genetic composition.Various molecular marker techniques may be used in combination toenhance overall resolution.

One use of molecular markers is Quantitative Trait Loci (QTL) mapping.QTL mapping is the use of markers, which are known to be closely linkedto alleles that have measurable effects on a quantitative trait.Selection in the breeding process is based upon the accumulation ofmarkers linked to the positive effecting alleles and/or the eliminationof the markers linked to the negative effecting alleles from the plant'sgenome.

Molecular markers can also be used during the breeding process for theselection of qualitative traits. For example, markers closely linked toalleles or markers containing sequences within the actual alleles ofinterest can be used to select plants that contain the alleles ofinterest during a backcrossing breeding program. The markers can also beused to select for the genome of the recurrent parent and against thegenome of the donor parent. Using this procedure can minimize the amountof genome from the donor parent that remains in the selected plants. Itcan also be used to reduce the number of crosses back to the recurrentparent needed in a backcrossing program. The use of molecular markers inthe selection process is often called genetic marker enhanced selection.Molecular markers may also be used to identify and exclude certainsources of germplasm as parental varieties or ancestors of a plant byproviding a means of tracking genetic profiles through crosses.

Production of Double Haploids

The production of double haploids may also be used for the developmentof plants with a homozygous genotype and/or phenotype in the breedingprogram. For example, a tomato plant for which tomato rootstock variety‘RTS-123’ is a parent can be used to produce double haploid plants.Double haploids are produced by the doubling of a set of chromosomes (1N) from a heterozygous plant to produce a completely homozygousindividual. For example, see Wan et al., “Efficient Production ofDoubled Haploid Plants Through Colchicine Treatment of Anther-DerivedMaize Callus”, Theoretical and Applied Genetic, 77:889-892, 1989 andU.S. Pat. No. 7,135,615. This can be advantageous because the processomits the generations of selfing needed to obtain a homozygous plantfrom a heterozygous source.

Haploid induction systems have been developed for various plants toproduce haploid tissues, plants and seeds. The haploid induction systemcan produce haploid plants from any genotype by crossing a selected line(as female) with an inducer line. Such inducer lines for maize includeStock 6 (Coe, 1959, Am. Nat. 93:381-382; Sharkar and Coe, 1966, Genetics54:453-464), KEMS (Deimling, Roeber, and Geiger, 1997, Vortr.Pflanzenzuchtg 38:203-224), or KMS and ZMS (Chalyk, Bylich & Chebotar,1994, MNL 68:47; Chalyk & Chebotar, 2000, Plant Breeding 119:363-364),and indeterminate gametophyte (ig) mutation (Kermicle 1969 Science166:1422-1424).

Methods for obtaining haploid plants are also disclosed in Kobayashi, M.et al., Journ. Heredity 71(1):9-14, 1980, Pollacsek, M., Agronomie(Paris) 12(3):247-251, 1992; Cho-Un-Haing et al., Journ. of Plant Biol.,1996, 39(3):185-188; Verdoodt, L., et al., February 1998, 96(2):294-300;Genetic Manipulation in Plant Breeding, Proceedings InternationalSymposium Organized by EUCARPIA, Sep. 8-13, 1985, Berlin, Germany;Chalyk et al., 1994, Maize Genet Coop. Newsletter 68:47; Chalyk, S.

Thus, an embodiment of this disclosure is a process for making asubstantially homozygous tomato rootstock variety ‘RTS-123’ progenyplant by producing or obtaining a seed from the cross of a tomato plantof tomato rootstock variety ‘RTS-123’ and another tomato plant andapplying double haploid methods to the F1 seed or F1 plant or to anysuccessive filial generation. Based on studies in maize and currentlybeing conducted in tomato, such methods would decrease the number ofgenerations required to produce a variety with similar genetics orcharacteristics to tomato rootstock variety ‘RTS-123’. See Bernardo, R.and Kahler, A. L., Theor. Appl. Genet. 102:986-992, 2001. In particular,a process of making seed retaining the molecular marker profile oftomato rootstock variety ‘RTS-123’ is contemplated, such processinvolving obtaining or producing F1 seed for which tomato rootstockvariety ‘RTS-123’ is a parent, inducing doubled haploids to createprogeny without the occurrence of meiotic segregation, obtaining themolecular marker profile of tomato rootstock variety ‘RTS-123’, andselecting progeny that retain the molecular marker profile of tomatorootstock variety ‘RTS-123’.

Descriptions of other breeding methods that are commonly used fordifferent traits and crops can be found in one of several referencebooks (e.g., Allard, 1960; Simmonds, 1979; Sneep et al., 1979; Fehr,1987).

The use of the terms “a,” “an,” and “the,” and similar referents in thecontext of describing the disclosure (especially in the context of thefollowing claims) are to be construed to cover both the singular and theplural, unless otherwise indicated herein or clearly contradicted bycontext. The terms “comprising,” “having,” “including,” and “containing”are to be construed as open-ended terms (i.e., meaning “including, butnot limited to,”) unless otherwise noted. Recitation of ranges of valuesherein are merely intended to serve as a shorthand method of referringindividually to each separate value falling within the range, unlessotherwise indicated herein, and each separate value is incorporated intothe specification as if it were individually recited herein. Forexample, if the range 10-15 is disclosed, then 11, 12, 13, and 14 arealso disclosed. All methods described herein can be performed in anysuitable order unless otherwise indicated herein or otherwise clearlycontradicted by context. The use of any and all examples, or exemplarylanguage (e.g., “such as”) provided herein, is intended merely to betterilluminate the embodiments of the disclosure and does not pose alimitation on the scope of the disclosure unless otherwise claimed. Nolanguage in the specification should be construed as indicating anynon-claimed element as essential to the practice of the embodiments ofthe disclosure.

While a number of exemplary aspects and embodiments have been discussedabove, those of skill in the art will recognize certain modifications,permutations, additions, and sub-combinations thereof. It is thereforeintended that the following appended claims and claims hereafterintroduced are interpreted to include all such modifications,permutations, additions, and sub-combinations as are within their truespirit and scope.

DEPOSIT INFORMATION

A deposit of tomato rootstock variety ‘RTS-123’ is maintained byRootility Ltd., having an address at P.O. Box 7104, Southern IndustrialZone Ashkelon, 7817001, Israel. Access to the deposit will be availableduring the pendency of this application to persons determined by theCommissioner of Patents and Trademarks to be entitled thereto under 37C.F.R. §1.14 and 35 U.S.C. §122. Upon allowance of any claims in thisapplication, all restrictions on the availability to the public oftomato rootstock variety ‘RTS-123’ will be irrevocably removed byaffording access to a deposit of at least 2,500 seeds of the varietywith the American Type Culture Collection, (ATCC), ATCC PatentDepository, 10801 University Boulevard, Manassas, Va., 20110, USA.

At least 2500 seeds of tomato rootstock variety ‘RTS-123’ were depositedon DATE according to the Budapest Treaty in the American Type CultureCollection (ATCC), ATCC Patent Depository, 10801 University Boulevard,Manassas, Va., 20110, USA. The deposit has been assigned ATCC number X1.Access to this deposit will be available during the pendency of thisapplication to persons determined by the Commissioner of Patents andTrademarks to be entitled thereto under 37 C.F.R. §1.14 and 35 U.S.C.§122. Upon allowance of any claims in this application, all restrictionson the availability to the public of the variety will be irrevocablyremoved.

The deposit will be maintained in the ATCC depository, which is a publicdepository, for a period of 30 years, or 5 years after the most recentrequest, or for the effective life of the patent, whichever is longer,and will be replaced if a deposit becomes nonviable during that period.

1. Tomato seed designated as ‘RTS-123’, representative sample of seedhaving been deposited under ATCC Accession Number X1.
 2. A plantproduced by growing the seed of claim
 1. 3. A plant part from the plantof claim
 2. 4. The plant part of claim 3, wherein said part is selectedfrom the group consisting of rootstocks, leaves, ovules, pollen, fruit,cotyledons, embryos, meristems, anthers, roots, root tips, pistils,flowers, stems, calli, stalks, hypocotyls, pericarps, and portionsthereof.
 5. A rootstock of the plant of claim
 2. 6. A tomato planthaving all the physiological and morphological characteristics of thetomato plant of claim
 2. 7. A plant part from the plant of claim
 6. 8.The plant part of claim 7, wherein said part is selected from the groupconsisting of rootstocks, leaves, ovules, pollen, fruit, cotyledons,embryos, meristems, anthers, roots, root tips, pistils, flowers, stems,calli, stalks, hypocotyls, and pericarps.
 9. The plant of claim 6,wherein said plant is a transgenic plant.
 10. An F₁ hybrid tomato planthaving ‘RTS-123’ as a parent where ‘RTS-123’ is grown from the seed ofclaim
 1. 11. The F₁ hybrid tomato plant of claim 10, wherein said plantis a transgenic plant.
 12. Pollen of the plant of claim
 2. 13. An ovuleof the plant of claim
 2. 14. A tissue culture of the plant of claim 2.15. A method of making tomato seeds comprised of crossing the plant ofclaim 2 with another tomato plant and harvesting seed therefrom.
 16. Themethod of claim 15, wherein at least one of said plants is transgenic.17. A method of making tomato rootstock variety ‘RTS-123’, said methodcomprising selecting seeds from the cross of one ‘RTS-123’ plant withanother ‘RTS-123’ plant, a sample of ‘RTS-123’ tomato seed having beendeposited under ATCC Accession Number X1.
 18. A tomato plant comprisinga rootstock and a scion engrafted onto the rootstock, wherein saidrootstock is from tomato rootstock variety ‘RTS-123’, representativesample of ‘RTS-123’ tomato seed having been deposited under ATCCAccession Number X1.